Remember to copy stuff on to your CHEAT SHEET!!!
Here is my answer key to the review:
Also, here is the key for the review for the quiz:
Wednesday, November 18, 2015
Unit 4 test review!
Test is Thursday/Friday.
Remember to copy stuff on to your CHEAT SHEET!!!
Here is my answer key to the review:
I've included the last page of Ms. Johnson's review, because I didn't write down the examples for the vocabulary on mine. :)
Also, here is the key for the review for the quiz:
Remember to copy stuff on to your CHEAT SHEET!!!
Here is my answer key to the review:
Also, here is the key for the review for the quiz:
Thursday, November 12, 2015
Revew Questions for the Friday / Monday Quiz!
Here are some questions for you to consider. If you can do these, you should be fine for the quiz.
Obviously, ask for help on the GroupMe or in person, if you get stuck.
Some things require the graphing calculator, and you may not have one at home. If I were you I would just make sure you write down the STEPS, since you can use notes on a quiz. :)
Also, for the calculator stuff - here's another copy of the poster I made in the classroom:
Obviously, ask for help on the GroupMe or in person, if you get stuck.
Some things require the graphing calculator, and you may not have one at home. If I were you I would just make sure you write down the STEPS, since you can use notes on a quiz. :)
Wednesday, November 11, 2015
Statistics (unit 3) - a few vocabulary words to remember (this is NOT all of them!!!)
Sampling method (how you sample the total population) :
(1) Simple random - think of a raffle. Put all the names in a hat and pull some out randomly.
(2) Stratified -
Split the population into groups: Say, all the 1A block classes at MHS
Then take A FEW RANDOM PEOPLE FROM EVERY GROUP.
(3) Cluster - also involves groups, but it's very different!
Split the population into groups: Say, all the 1A block classes at MHS
Then choose a FEW GROUPS and take EVERY SINGLE PERSON in those groups.
(4) Systematic - think of the lunch line. Choose a random person to start, then take every 3rd person, every 10th person, or count by whatever set number to get your sample.
(5) Convenience - just what it sounds like. Take the easiest participants to get.
Observational vs. Experimental
Observational is when you are only observing, not doing. You might be watching or listening in person, using a microphone or a camera, asking survey questions. But you are not changing what's happening (except maybe by accident, through biased survey questions or observer effect).
Experimental is when you set up a control group and a treatment group (or more than one) and you are actually doing something to see what happens as a result of a specific treatment.
Open vs. Closed
If they have to choose from a selection of set answers (multiple choice, true/false, yes/no, "on a scale of 0 to 10"), it's closed. If they can say whatever they want, it's open.
Observer effect
When people change what they do or say because they're being watched.
Sampling bias
When you don't have a representative sample (only allowing men to vote, for instance), and this changes the results of the study.
Statistical bias
When a study is inaccurate because of problems with the tools or method - the scale for the potato chip study, or biased survey questions like "Isn't Marietta High School the best school in the state?"
Placebo - what's given in the place of the treatment (think: sugar pill in place of medicine).
Placebo effect - when even the placebo causes a change, because the participant believes there will be an effect.
Any other terms you're not sure about? Please ask us on the GroupMe!
Tuesday, October 27, 2015
Unit 2 test, answer key.
Here is my answer key for the test review. I know Ms. Johnson sent hers out, but sometimes there are more than one way to get the same answer, so here is mine for comparison.
* Please note on page 5, if you had looked at my answer key already - I got one of them wrong. This image shows the correction, in blue ink!
Thursday, October 8, 2015
Probability Unit, continued... Pascal's triangle, theoretical probability, expected value.
Here are some things to help you with the homework assignments, or your project:
We did a problem about a guy who had 5 chances to hit a pitched baseball. We did it with both a tree:
and with Pascal's triangle:
Pascal's triangle is useful whenever you have a BINOMIAL game (hit/miss, even/odd, yes/no, heads/tails) where both probabilities are equally likely.
NOTE: If your game is NOT binomial, there are other methods to use. We will get to them Thursday/Friday (today and tomorrow) in class.
No matter what kind of game you have, your report should include a budget section like this:
There was a homework assignment about a girl shooting baskets for different $ allowance values. Here are the pictures from that:
On the first shot, she will make the basket 60% of the time, and miss 40% of the time. So 40 of the 100 boxes in the area model are marked off, and the reward for that is just $5.
If she makes the first shot (60 of the original 100 boxes), she will make the next shot 60% of the time.
60% = 0.60. 0.60(60) = 36, so in 36 of the original 100 boxes, she gets the full $25. That's 36%.
40% of the time she misses that 2nd shot. 40% = 0.40. 0.40(60) = 24, so in 24 of the original boxes she gets the $15 reward (according to the rules of the game). That's 24%
Note, 40% + 36% + 24% = 100%.
She does that every week for a year (52 weeks):
In theory, she will earn just $5 in 40% of those 52 weeks: 0.40(52)*$5 = $104.00
In theory, she will earn $15 in 24% of those 52 weeks: 0.24(52)*$15 = $187.20
In theory, she will earn the full $25 in 36% of those 52 weeks: 0.36(52)*$25 = $430.56
So, adding up all those means she can EXPECT to earn, over the year, a total VALUE of $759.20.
(The EXPECTED VALUE is $759.20)
We did a problem about a guy who had 5 chances to hit a pitched baseball. We did it with both a tree:
and with Pascal's triangle:
Pascal's triangle is useful whenever you have a BINOMIAL game (hit/miss, even/odd, yes/no, heads/tails) where both probabilities are equally likely.
NOTE: If your game is NOT binomial, there are other methods to use. We will get to them Thursday/Friday (today and tomorrow) in class.
No matter what kind of game you have, your report should include a budget section like this:
There was a homework assignment about a girl shooting baskets for different $ allowance values. Here are the pictures from that:
If she makes the first shot (60 of the original 100 boxes), she will make the next shot 60% of the time.
60% = 0.60. 0.60(60) = 36, so in 36 of the original 100 boxes, she gets the full $25. That's 36%.
40% of the time she misses that 2nd shot. 40% = 0.40. 0.40(60) = 24, so in 24 of the original boxes she gets the $15 reward (according to the rules of the game). That's 24%
Note, 40% + 36% + 24% = 100%.
She does that every week for a year (52 weeks):
In theory, she will earn just $5 in 40% of those 52 weeks: 0.40(52)*$5 = $104.00
In theory, she will earn $15 in 24% of those 52 weeks: 0.24(52)*$15 = $187.20
In theory, she will earn the full $25 in 36% of those 52 weeks: 0.36(52)*$25 = $430.56
So, adding up all those means she can EXPECT to earn, over the year, a total VALUE of $759.20.
(The EXPECTED VALUE is $759.20)
Tuesday, September 29, 2015
Quiz review - Unit 2 Quiz A
Here are some review problems for anyone who wants them, for the quiz on Wednesday/Thursday. There are also many practice problems in your packet.
Wednesday, September 23, 2015
More Practice
*** Remember there will be a quiz on September 30 (B day) or October 1 (A day) on the (1) Venn diagrams, (2) tree diagrams, and (3) area diagrams.
Here are some of the examples we did in class. I strongly encourage you to look through them, make sure you understand them (ask questions in class or on group me if you need help!) and, especially for the area diagrams, try some of the other ones in the packet.
Venn Diagrams:
Tree diagrams:
Area diagrams:
Here are some of the examples we did in class. I strongly encourage you to look through them, make sure you understand them (ask questions in class or on group me if you need help!) and, especially for the area diagrams, try some of the other ones in the packet.
Venn Diagrams:
Friday, September 18, 2015
Tree and area diagrams
Here are the examples from today (or Monday for A day people).
TREE DIAGRAMS:
AREA DIAGRAMS:
TREE DIAGRAMS:
AREA DIAGRAMS:
Thursday, September 17, 2015
Venn Diagrams
New unit: We're on probability. Here are some graphics to help you out with the Venn diagrams. Remember to watch for those "magic" words!
Wednesday, September 2, 2015
"What's on the test?"
That's a very good question. Here you go. The test is Thursday September 10 (1A, 2A, 4A) and Friday September 11 (1B, 2B, and 3B).
What's on it:
I think I now have an example and a practice problem for each of these.
You can use this to study and practice.
Please ask me or Ms. Johnson for help - in class, after school, or on group me!
Also, I'm only human - if you think you've found a mistake, please let me know so I can fix it!
Step 1: Find the total area:
square = 500 ft * 500 ft = 250,000 ft^2
MPC = 15 ft * 25ft = 375 ft^2
+ _________________________________
250,375 ft^2
Step 2: Set up the ratios and cross-multiply to solve for x, the total number of people
1 person / 3 ft^2 = X people / 250,375 ft^2
3 ft^2 * X people = 1 person * 250,375 ft^2
X people = 1 person *250,375 ft^2 / 3 ft^2 = 83458.333 people, which rounds to
83,458 people
You Try:
The MHS homecoming parade comes down Polk St. People crowd both sides of the street for a length of 0.5 miles, 5 feet back. There are 5280 feet in a mile! If each person has about 2.2 square feet of space, estimate the total number of people. This one is like the one on the first quiz!
step 1: the volume of the room (in cubic INCHES - convert if and ONLY IF needed)
length = 40 ft (12 inches/ft) = 480 inches
width = 30 ft (12 inches/ft) = 360 inshes
height = 9.25 ft (12 inches/ft) = 111 inches
volume = length * width * height = 19180800 inches^3
step 2: the volume used by one ball (we basically assume a small cube holding one ball)
length = width = height = 3.5 inches (the diameter of one ball)
volume = 3.5 in * 3.5 in * 3.5 in = 42.875 inches^3
step 3: set up the ratio and cross-multiply:
1 ball / 42.875 in^3 = X balls / 19,180,800 in^3
42.875 in^3 * X balls = 1 ball * 19,180,800 in^3
X balls = 1 ball * 19180800 in^3 / 42.875 in^3 = 447,365.59 balls, which rounds to
447,366 balls.
You Try:
Sara's bedroom is 20 ft wide, 15 feet long, and 9.5 feet high. One balloon has a diameter of 10 inches. How many balloons could her annoying little sister fill her room with (assuming the balloons stack straight up in rows, the walls are flat, and the room is empty)?
H is set, not changing. So we don't care.
I is set, not changing. So we don't care
5 is set, not changing. So we don't care.
{ } has 9 possibilities (1,2,3,4,5,6,7,8,9)
# has 10 possibilities (0,1,2,3,4,5,6,7,8,9), AND there are 5 of them!
[] has 26 possibilities (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z)
total possibilities = 9*10*10*10*10*10*26 = 23,400,000
You Try:
Phone numbers in Switzerland follow a pattern: 78 () # # # # # @, where () is any number 2-9 (not 0 or 1), # is any number 0-9, and @ is a 4 or a 5. How many different combinations are there?
Find the area of a 60 inch TV with a 16:9 aspect ratio.
60 inches is the diagonal. The width is 16x and the height is 9x
(from the aspect ratio we know that they are 16 and 9 times some unknown amount : x)
step 1: Set up Pythagorean Theorem and solve for x:
(16x)^2 + (9x)^2 = (60in)^2
256 x^2 + 81 x^2 = 3600 in^2 (square EVERYTHING)
377 x^2 = 3600 in^2 (combine like terms)
x^2 = 9.549 (divide both sides by the 377)
x = 3.090 (take the square root)
step 2: Plug back in and get the width and the height:
width = 16(3.090) = 49.44 INCHES (REMEMBER TO PUT UNITS!!!)
height = 9(3.090) = 27.81 INCHES
step 3: Multiply to get the area (A = W*H)
Area = 49.44 inches * 27.81 inches = 1374.926 inches^2
You Try: Find the area of a 48 inch TV with an aspect ratio of 4:3.
REMEMBER: There are always 25.4 mm per inch.
original tires: new tires:
width: 250 mm 270 mm
aspect ratio: 70%=0.70 73% = 0.73
height of the rubber: 250*0.70/25.4 = 6.890 in 270*0.73/25.4=7.760 in
diameter of the rim: 17 in 19 in
total diameter: 17 + 6.890 + 6.890 = 30.780 in 19 + 7.760 + 7.760 = 34.520 in
circumference: 30.780*pi = 96.698 inches 108.448 inches
ratio of the bigger to the smaller circumference: 108.448 in/ 96.698 in = 1.122
(NO UNITS for a ratio)
CORRECTED odometer reading = 14,000 miles * 1.122 = 15,708 miles
CORRECTED speedometer reading = 60 mph * 1.122 = 67.320 mph
You Try:
Your car came with P225/72R16 tires. You decide to replace them with P250/74R20. If your odometer reads 25,000 miles (the total distance you think you have driven) and your speedometer reads 75 miles per hour (the speed you think you are driving), what are your ACTUAL miles driven and speed?
step 1: test average: 70+80+82+60 = 292. 292/4 = 73 (divide by 4 because there are 4 of them)
(Any time you're given a list of scores, average them)
step 2: quiz average: 54+80 = 134 134/2 = 67
Step 3: multiply by the weights (as decimals, so divide by 100%!!), and add up the grade so far
73(0.60) = 43.8
67(0.15) = 10.05
75(0.05) = 3.75
+____________
57.6
Step 4: Add in the Final Exam (x) times the weight for that, set equal to the goal grade, and then solve for x
57.6 + 0.20x =73
-57.6 -57.6
___________________
0.20x = 15.4
divide both sides by 0.20: x = 77
You Try:
Geometry grades are 50% for tests, 20% for quizzes, 10% for homework, and 20% for the final exam. Kim has 3 test grades: 73, 85, 100. She has 4 quizzes: 88, 92, 99, 85. She has a 80 average for her homework. What does she need on the final exam to get a B (80 average) ?
12 Doubles 4 Triples 53 Singles 8 Home runs 300 At bats
QR = 25 + 10(%COMP) + 40(%TD) - 50(%INT) + 50(YD)
12
= 25 + 10(59.524) + 40(4.286) - 50(3.571) + 50(5.238) = 875.03/12 = 72.919
12
You Try:
Find the quarterback rating of a player with the following stats:
3(a1) + a2 + 3(a3) + a4 + 3(a5) + a6 + 3(a7) + a8 + 3(a9) + a10 + 3(a11) + d
3(8) + 3 + 3(2) + 9 + 3(4) + 6 + 3(7) + 3 + 3(2) + 0 + 3(8) + d
= 24 + 3 + 6 + 9 + 12 + 6 + 21 + 3 + 6 + 0 + 24 + d
= 114 + d
the total has to end in 0, so 114 + d = 120 (the next number that ends in 0)
d = 120 - 114 = 6.
You Try:
What is the last digit of the UPC 9 28363 45821 [d] ?
Find the last digit (the check digit) of the Visa number below so that it is valid:
2314 2463 8536 225[d]
step 1: add the digits in the ODD positions (1st, 3rd, 5th, 7th ... 15th)
2 + 1 + 2 + 6 + 8 + 3 + 2 + 5 = 29
step 2: double that number:
29*2 = 58
step 3: COUNT how many of those ODD positioned numbers are more than 4, and add that:
There are 3 that are more than 4: 6, 8, and 5. 58 + 3 = 61
step 4: add the digits in the EVEN positions (2nd, 4th, 6th, 8th ... 14th) to that total:
61 + 3 + 4 + 4 + 3 + 5 + 6 + 2 = 88
step 5: (just like UPC) find the digit you can add to make a total that ends in 0:
88 + d = 90
-88 -88
___________
d = 2
You Try:
Find the last digit (the check digit) of the Mastercard number below so that it is valid:
8234 3248 3255 324[d]
What's on it:
- Crowd size (from quiz #1)
- Tennis balls (from quiz #1)
- Phone numbers / license plates (from quiz #1)
- TV's (from quiz #2)
- Tires (from quiz #2)
- Grade weighting (new; Wed/Thurs)
- Baseball (new; Wed/Thurs)
- Football (new; Wed/Thurs)
- UPC's (new; Fri/Tues/Wed)
- Credit Cards (new; Fri/Tues/Wed)
- You should also be prepared to write sentences to discuss
- the real-world context of any of these problems, and
- assumptions made when trying to answer a big Fermi type question
I think I now have an example and a practice problem for each of these.
You can use this to study and practice.
Please ask me or Ms. Johnson for help - in class, after school, or on group me!
Also, I'm only human - if you think you've found a mistake, please let me know so I can fix it!
Examples:
Crowd size (from quiz #1)
Step 1: Find the total area:
square = 500 ft * 500 ft = 250,000 ft^2
MPC = 15 ft * 25ft = 375 ft^2
+ _________________________________
250,375 ft^2
Step 2: Set up the ratios and cross-multiply to solve for x, the total number of people
1 person / 3 ft^2 = X people / 250,375 ft^2
3 ft^2 * X people = 1 person * 250,375 ft^2
X people = 1 person *250,375 ft^2 / 3 ft^2 = 83458.333 people, which rounds to
83,458 people
You Try:
The MHS homecoming parade comes down Polk St. People crowd both sides of the street for a length of 0.5 miles, 5 feet back. There are 5280 feet in a mile! If each person has about 2.2 square feet of space, estimate the total number of people. This one is like the one on the first quiz!
Tennis balls (from quiz #1)
step 1: the volume of the room (in cubic INCHES - convert if and ONLY IF needed)
length = 40 ft (12 inches/ft) = 480 inches
width = 30 ft (12 inches/ft) = 360 inshes
height = 9.25 ft (12 inches/ft) = 111 inches
volume = length * width * height = 19180800 inches^3
step 2: the volume used by one ball (we basically assume a small cube holding one ball)
length = width = height = 3.5 inches (the diameter of one ball)
volume = 3.5 in * 3.5 in * 3.5 in = 42.875 inches^3
step 3: set up the ratio and cross-multiply:
1 ball / 42.875 in^3 = X balls / 19,180,800 in^3
42.875 in^3 * X balls = 1 ball * 19,180,800 in^3
X balls = 1 ball * 19180800 in^3 / 42.875 in^3 = 447,365.59 balls, which rounds to
447,366 balls.
You Try:
Sara's bedroom is 20 ft wide, 15 feet long, and 9.5 feet high. One balloon has a diameter of 10 inches. How many balloons could her annoying little sister fill her room with (assuming the balloons stack straight up in rows, the walls are flat, and the room is empty)?
Phone numbers / license plates (from quiz #1)
H is set, not changing. So we don't care.
I is set, not changing. So we don't care
5 is set, not changing. So we don't care.
{ } has 9 possibilities (1,2,3,4,5,6,7,8,9)
# has 10 possibilities (0,1,2,3,4,5,6,7,8,9), AND there are 5 of them!
[] has 26 possibilities (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z)
total possibilities = 9*10*10*10*10*10*26 = 23,400,000
You Try:
Phone numbers in Switzerland follow a pattern: 78 () # # # # # @, where () is any number 2-9 (not 0 or 1), # is any number 0-9, and @ is a 4 or a 5. How many different combinations are there?
TV's (from quiz #2)
Find the area of a 60 inch TV with a 16:9 aspect ratio.
60 inches is the diagonal. The width is 16x and the height is 9x
(from the aspect ratio we know that they are 16 and 9 times some unknown amount : x)
step 1: Set up Pythagorean Theorem and solve for x:
(16x)^2 + (9x)^2 = (60in)^2
256 x^2 + 81 x^2 = 3600 in^2 (square EVERYTHING)
377 x^2 = 3600 in^2 (combine like terms)
x^2 = 9.549 (divide both sides by the 377)
x = 3.090 (take the square root)
step 2: Plug back in and get the width and the height:
width = 16(3.090) = 49.44 INCHES (REMEMBER TO PUT UNITS!!!)
height = 9(3.090) = 27.81 INCHES
step 3: Multiply to get the area (A = W*H)
Area = 49.44 inches * 27.81 inches = 1374.926 inches^2
You Try: Find the area of a 48 inch TV with an aspect ratio of 4:3.
Tires (from quiz #2)
REMEMBER: There are always 25.4 mm per inch.
original tires: new tires:
width: 250 mm 270 mm
aspect ratio: 70%=0.70 73% = 0.73
height of the rubber: 250*0.70/25.4 = 6.890 in 270*0.73/25.4=7.760 in
diameter of the rim: 17 in 19 in
total diameter: 17 + 6.890 + 6.890 = 30.780 in 19 + 7.760 + 7.760 = 34.520 in
circumference: 30.780*pi = 96.698 inches 108.448 inches
ratio of the bigger to the smaller circumference: 108.448 in/ 96.698 in = 1.122
(NO UNITS for a ratio)
CORRECTED odometer reading = 14,000 miles * 1.122 = 15,708 miles
CORRECTED speedometer reading = 60 mph * 1.122 = 67.320 mph
You Try:
Your car came with P225/72R16 tires. You decide to replace them with P250/74R20. If your odometer reads 25,000 miles (the total distance you think you have driven) and your speedometer reads 75 miles per hour (the speed you think you are driving), what are your ACTUAL miles driven and speed?
Grade weighting (new; Wed/Thurs)
step 1: test average: 70+80+82+60 = 292. 292/4 = 73 (divide by 4 because there are 4 of them)
(Any time you're given a list of scores, average them)
step 2: quiz average: 54+80 = 134 134/2 = 67
Step 3: multiply by the weights (as decimals, so divide by 100%!!), and add up the grade so far
73(0.60) = 43.8
67(0.15) = 10.05
75(0.05) = 3.75
+____________
57.6
Step 4: Add in the Final Exam (x) times the weight for that, set equal to the goal grade, and then solve for x
57.6 + 0.20x =73
-57.6 -57.6
___________________
0.20x = 15.4
divide both sides by 0.20: x = 77
You Try:
Geometry grades are 50% for tests, 20% for quizzes, 10% for homework, and 20% for the final exam. Kim has 3 test grades: 73, 85, 100. She has 4 quizzes: 88, 92, 99, 85. She has a 80 average for her homework. What does she need on the final exam to get a B (80 average) ?
Baseball (new; Wed/Thurs)
My nephew is in junior baseball. He has the following stats for this season:12 Doubles 4 Triples 53 Singles 8 Home runs 300 At bats
Find the Slugging Percentage.
SLG = (1*S) + (2*D) + (3*T) + (4*HR)
AB
= (1*53) + (2*12) + (3*4) + (4*8) = 121/300 = 0.40333333
300
To get in as a percent, multiply by 100%: 0.40333333 * 100% = 40.333%
You Try: His older brother is in the same league. He has the following stats out for this season:
12 Doubles 4 Triples 53 Singles 8 Home runs 300 At bats
12 Doubles 4 Triples 53 Singles 8 Home runs 300 At bats
Find the Slugging Percentage.
Football (new; Wed/Thurs)
Find
the quarterback rating of a player with the following stats:
- 250 completed passes in 420 attempts
- Total of 2200 yards
- 18 touchdowns and
- 15 interceptions
Percent of total completions
(%COMP)= 250/420 * 100% = 59.524%
Percent of total touchdowns
(%TD)= 18/420 * 100% = 4.286%
Percent of interceptions per
attempt (%INT)= 15/420 * 100% = 3.571%
Average yards gained per
attempt (YD)= 2200/420 = 5.238 (yds)
Quarterback rating: (It's a long formula, but then you just plug in!)
QR = 25 + 10(%COMP) + 40(%TD) - 50(%INT) + 50(YD)
12
= 25 + 10(59.524) + 40(4.286) - 50(3.571) + 50(5.238) = 875.03/12 = 72.919
12
You Try:
Find the quarterback rating of a player with the following stats:
- 325 completed passes in 510 attempts
- Total of 2805 yards
- 22 touchdowns and
- 17 interceptions
UPC's (new; Tues/Wed)
3(a1) + a2 + 3(a3) + a4 + 3(a5) + a6 + 3(a7) + a8 + 3(a9) + a10 + 3(a11) + d
3(8) + 3 + 3(2) + 9 + 3(4) + 6 + 3(7) + 3 + 3(2) + 0 + 3(8) + d
= 24 + 3 + 6 + 9 + 12 + 6 + 21 + 3 + 6 + 0 + 24 + d
= 114 + d
the total has to end in 0, so 114 + d = 120 (the next number that ends in 0)
d = 120 - 114 = 6.
You Try:
What is the last digit of the UPC 9 28363 45821 [d] ?
Credit Cards (new; Tues/Wed)
Find the last digit (the check digit) of the Visa number below so that it is valid:
2314 2463 8536 225[d]
step 1: add the digits in the ODD positions (1st, 3rd, 5th, 7th ... 15th)
2 + 1 + 2 + 6 + 8 + 3 + 2 + 5 = 29
step 2: double that number:
29*2 = 58
step 3: COUNT how many of those ODD positioned numbers are more than 4, and add that:
There are 3 that are more than 4: 6, 8, and 5. 58 + 3 = 61
step 4: add the digits in the EVEN positions (2nd, 4th, 6th, 8th ... 14th) to that total:
61 + 3 + 4 + 4 + 3 + 5 + 6 + 2 = 88
step 5: (just like UPC) find the digit you can add to make a total that ends in 0:
88 + d = 90
-88 -88
___________
d = 2
You Try:
Find the last digit (the check digit) of the Mastercard number below so that it is valid:
8234 3248 3255 324[d]
Tuesday, September 1, 2015
Calculating Grades - NEW ASSIGNMENT AFTER THIS WEEK'S QUIZ
The quiz grades were pretty good! On average, they were better than last time, which for most of you will bring up your average in the "quiz" category in the grade book.
Speaking of grades ... That's what we're doing next. It's pages 17, 18, and 18A in your packet. Please come prepared to go over that in class next time.
If you don't have those pages, here they are:
Here's another example, from my actual grade categories for this class:
Assessments (tests and major projects) : 60% <<< These are the CATEGORY WEIGHTS
Daily assignments and quizzes: 20%
Final exam: 20%
To calculate a student's grade, (1) multiply their grade in each category by that category's weight, as a DECIMAL, then (2) add them all up.
So if a student has a 70 average on daily grades and quizzes, but an 80 average on tests, and they get a 78 on the final, their grade will be:
70*.60 = 42
80*.20 = 16
78*.20 = 15.6
+ __________
73.6, which would round to a 74.
If a student has a 75 average on daily and quizzes, and a 78 average on tests, what do they need to get on the final to get a B?
75*.60 = 45
78*.20 = 15.6
[x]*.20 = 0.20X
+____________
60.6 + 0.20X = 80 (a B) <<< now we solve for X, the final exam grade needed.
-60.6 -60.6
___________________________
0.20X = 19.6
/0.2 /0.20
X = 98.
The student would need to get a 98 on the final exam to get a B for the class.
Speaking of grades ... That's what we're doing next. It's pages 17, 18, and 18A in your packet. Please come prepared to go over that in class next time.
If you don't have those pages, here they are:
Assessments (tests and major projects) : 60% <<< These are the CATEGORY WEIGHTS
Daily assignments and quizzes: 20%
Final exam: 20%
To calculate a student's grade, (1) multiply their grade in each category by that category's weight, as a DECIMAL, then (2) add them all up.
So if a student has a 70 average on daily grades and quizzes, but an 80 average on tests, and they get a 78 on the final, their grade will be:
70*.60 = 42
80*.20 = 16
78*.20 = 15.6
+ __________
73.6, which would round to a 74.
If a student has a 75 average on daily and quizzes, and a 78 average on tests, what do they need to get on the final to get a B?
75*.60 = 45
78*.20 = 15.6
[x]*.20 = 0.20X
+____________
60.6 + 0.20X = 80 (a B) <<< now we solve for X, the final exam grade needed.
-60.6 -60.6
___________________________
0.20X = 19.6
/0.2 /0.20
X = 98.
The student would need to get a 98 on the final exam to get a B for the class.
Thursday, August 27, 2015
Welcome!
Hello -
I'm hoping to use this blog to post useful information and examples, so I don't blow up GroupMe on your phones.
Group me will be used only for short reminders, and for you asking for help. Also remember that you can turn off notifications!
From today/tomorrow: We looked at how the size of tire you use can change the accuracy of your speedometer. Here is the example from class.
There is a quiz on Monday/Tuesday. It will include (1) areas and aspect ratios of TVs, and (2) tire problems like this.
I'm hoping to use this blog to post useful information and examples, so I don't blow up GroupMe on your phones.
Group me will be used only for short reminders, and for you asking for help. Also remember that you can turn off notifications!
From today/tomorrow: We looked at how the size of tire you use can change the accuracy of your speedometer. Here is the example from class.
There is a quiz on Monday/Tuesday. It will include (1) areas and aspect ratios of TVs, and (2) tire problems like this.
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