Math 8
Assignment Worksheet
Unit 12
Using a pencil, answer the following questions. This assignment is marked, based on effort, work shown where possible, completeness, neatness, and accuracy. Do your best!
For the following questions, compare the graphs, stating the strengths of the graph you think are better for the given data.
1.
Below is information regarding the lengths of several telephone conversations. a) Which of the graphs best represents the data? The bar or the pie? b) What are two strengths of the graph you chose as the best?
Page 1 of 10

Math 8
Assignment Worksheet
Unit 12
2.
Below are two graphs of newspaper sales over various years. Which graph best represents the data? a) Which of the graphs best represents the data? The bar or the line? b) What are two strengths of the graph you chose?
Page 2 of 10

Math 8
Assignment Worksheet
Unit 12
When data is presented in a graphical format, there can be weaknesses in the method chosen. For the following questions, state both the strengths and weaknesses of the graphical method chosen.
1.
For the graph above, there are several benefits to presenting the data in this manner.
What are some of these?
2.
There are also several weaknesses, what are some of these?
3.
Do you feel that the data has been misrepresented? If so, how?
4.
If you could make only one change to the graph, what would it be? Why this change?
Page 3 of 10

Math 8
Assignment Worksheet
Unit 12
Below is a graph that shows how many different sports various grade 12 students take part in after school. A sample of 49 students were questioned from various P.E. classes at a single high school in Vancouver, BC. State whether you agree or disagree with the conclusions drawn below, and why.
1.
The data clearly shows that over half of the students questioned play two different sports.
2.
The data clearly shows that over half of the grade 12 students in Vancouver play two different sports.
3.
The data clearly shows that grade 12 students can be expected to play at least one sport.
4.
The data clearly shows that students in P.E. classes are more likely to play sports than those that are not in P.E.
Page 4 of 10

Math 8
Assignment Worksheet
Unit 12
1.
Make an outcome table AND a tree diagram to show the possible outcomes of flipping a coin and then rolling a six-sided die. Then answer the questions below. a. How many different outcomes are there? b. What is the probability of tossing a tail and rolling a 4? P(tails, 4) c. What is the probability of tossing heads and rolling an even number? P(heads, even)
Page 5 of 10

Math 8
Assignment Worksheet
Unit 12
2. Make a tree diagram and an outcome table to show the results of rolling the die and spinning the spinner. blue green yellow red a. What is the probability of spinning blue and rolling 1? P(blue,1) b. What is the probability of spinning either red or yellow AND rolling an even number?
Page 6 of 10

Math 8
Assignment Worksheet
Unit 12
3. What is the probability of drawing an ace from a stack of 52 playing cards and then rolling a six on a six sided die (there are 4 aces in a stack of 52 playing cards)?
It is always a good idea to verify a calculation before accepting the answer as true. Solve the following probabilities by drawing a tree diagram and multiplying using the formula.
1.
What is the probability of flipping a coin three times and having a head-tail-tail appear in order?
2. If you have a four sided die (in the shape of a pyramid) with the sides numbered 1, 2, 3, 4 what is the probability of rolling a one-two-three in order? P(1,2,3)
Page 7 of 10

Math 8
Assignment Worksheet
Unit 12
3. A bag contains 4 yellow balls, 2 red balls, and 3 green balls. Without looking a ball is chosen from the bag, then returned to the bag. A second and then a third ball is drawn. a. What is the probability of selecting a yellow ball followed by a green ball? b. What is the probability of selecting a yellow ball, then a red ball, then a green ball?
Solve the following word problem using your knowledge of probabilities.
1.
Tanner has 20 songs in his MP3 player. There are 6 rock songs, 4 rap songs, 3 classical and 7 country. He sets the player to select the songs randomly, which means that each song has an EQUAL chance of being selected even if it has already played. a. What is probability of hearing songs in this order: rock, rap, country? b. What is the probability of hearing the same song twice in a row? c. What is the probability of hearing 2 classical songs in a row, then 1 rap song?
Page 8 of 10

Math 8
Assignment Worksheet
Unit 12
2. It’s a contest! If the total of 3 of your spins is 100 or more you win a prize! What is the probability that you’ll win? P(100 or more on 3 spins). Because the results of the 3 spins are only known at the end you’ll need to draw a tree diagram to arrive at your answer.
Multiplying the probabilities together won’t work because it’s a TOTAL amount.
Page 9 of 10

Math 8
Assignment Worksheet
Unit 12
3. The probability of precipitation is the chance that it may rain (or snow). It is included on weather charts as POP or probability of precipitation.
What is the probability that it will rain in all three cities tomorrow?
4. The combination lock has 2 spinning dials with the digits 0-9 on each. a. What’s the probability of guessing the combination on the first try? (Show your work) b. If there were 3 dials with 0-9, what would be the probability of guessing the combination on the first try?
Answers Section One:
A) 1)a) Bar
B) 1) Easy to see trend of increase, years clearly separated 3) Yes, scale of axis does not start at zero, looks like huge increase when its only about $8000 change
C) 1) Agree, information supported by sample questioned 3) Disagree, not enough grade 12 students were questioned and all data from only one type of class
Answers Section Two:
A: 1a) 12 1b) 1/12 1c) ¼ 3) 1/78 B: 1) 1/8 3a) 4/27 3b) 8/243 C. 1a) 21/1000 1b)1/400 1c) 9/2000 3) 4/125
Page 10 of 10