7th Grade Statistics & Probability Chapter Questions
1. How can the collection, organization and display of data help to interpret, evaluate inferences and make predictions about real-life situations and circumstances?
2. How does probability relate to real world application problems?
3. How can measures of center and variation be used to compare two sets of data?
4. How are different events classified and what can I use to solve them?
5. How can finding the ways to count the possible outcomes of compound events be used to determine their probability?
Chapter Problems
Introduction to Probability
Classwork
A jar contains 6 red, 8 blue, one white, 7 black, and two yellow marbles.
Use this information to determine the probability of selecting:
1) a white marble
2) a red marble
3) a yellow marble
4) a purple marble
5) a black marble
Homework
A spinner is divided into 8 sections of equal size. The sections are numbered 1 through 8.
Use this information to determine the probability of the needle landing on:
6) section 7
7) an even numbered section
8) section 1, 2, 3, or 4
9) section 9
10) section 8
Experimental and Theoretical Probability
Classwork
11) A die is rolled. Complete the table.
Roll / Theoretical Probability1
2
3
4
5
6
12) A die is rolled 10 times and the outcomes are:
Outcome / Number of TimesRoll 1 / 0
Roll 2 / 3
Roll 3 / 1
Roll 4 / 3
Roll 5 / 2
Roll 6 / 1
Use the above table to find the experimental probability for the following questions.
a. rolling a 1
b. rolling a 2
c. rolling a 3
d. rolling a 4
e. rolling a 5
Homework
A spinner contains 8 equally divided sections, two sections have the letter A, 3 sections have the letter B, one section has the letter C, one section has the letter D, and one section has the letter E.
13) Draw a picture of the spinner.
14) Use your drawing to fill in the chart.
Spin / Theoretical ProbabilityA
B
C
D
E
15) The spinner is spun 10 times and the outcomes are:
Outcome / Number of TimesA / 4
B / 1
C / 3
D / 2
E / 0
Use the table above to find the experimental probability for the following questions.
a. spinning an A
b. spinning a B
c. spinning a C
d. spinning a D
e. spinning an E
Sampling
Classwork
16) In a survey of 300 voters, 68 said they voted for Candidate A. How many votes can Candidate A expect to receive if the population of the town is 10,000?
17) In a capture-recapture study, 97 grizzly bears were tagged and released back into the wild. A month later, 200 bears were captured of which 36 were tagged. About how many grizzly bears are in the population?
18) From a survey of 100 commuters about how they get to work, 38 said they drive their cars, 47 said they take the bus, 14 said they take the subway, and 1 said they ride their bicycle. Out of 4,800 commuters, predict how many will commute to work in each of the following way.
a. Car
b. Bus
c. Subway
d. Bicycle
19) To determine the consistency of a printer, 100 printed sheets are randomly checked and 4 sheets are defective. Is this sample reliable? About how many defective sheets would be expected if 2,400 sheets were printed?
20) The cafeteria employees would like to start selling fruit in the morning. They surveyed 24 students by asking every 8th student that entered the cafeteria for breakfast. Four students said they preferred apples, 3 preferred oranges, and 1 preferred peaches. If 336 students purchase breakfast daily, about how many students can they expect to pick an orange?
Homework
21) In a capture-recapture study, 83 mountain lions were tagged and released back into the wild. Several months later, 300 mountain lions were captured, of which 54 were tagged. About how many mountain lions are in the population?
22) In a survey of 1056 voters at Roberts School, 274 said they voted for Candidate A. How many votes can Candidate A expect to receive if there were 5,101 votes?
23) From a survey of 80 students about their favorite subjects, 24 said Language Arts, 16 said Science, 31 said Mathematics, and 9 said Social Studies. Out of 960 students, predict how many will favor each subject.
a. Language Arts
b. Science
c. Mathematics
d. Social Studies
24) A DVD player manufacturing company wants to test the quality of their DVD players. They randomly pick 50 DVD players to test and determine that 4 are defective. Is this sample reliable? About how many defective DVD players would you expect if 1,000 DVD players are made?
25) A library wants to expand their children’s book section. The librarians surveyed 30 children by asking every 6th child that visited the library to figure out what genres were most popular. The children’s responses were: 12 liked fiction, 8 liked non-fiction, 4 liked science fiction, and 6 liked mystery. If the library expects 540 children to visit the library in a week, about how many children will check out a mystery book?
Word Problems
Classwork
26) You made 8 out of 15 shots on goal. Use experimental probability to predict how many goals you will make tomorrow if you take 70 shots.
27) There are 1000 buttons in the jar. You randomly select 10 buttons and get 3 red, 4 blue, 2 white, 1 black. Use experimental probability to predict how many buttons in the jar are:
- Red
- Blue
- White
- Black
28) A die is rolled. What is the theoretical probability for rolling a 3?
Mary rolls a die six times and rolls a 3, on two of the rolls. What is the experimental probability for rolling a 3?
29) Create a situation where the experimental probability and the theoreticalprobability have the same value.
30) A coin is flipped. What is thetheoretical probability for flipping a tail?
Mark and John flip a coin twenty times and get 8heads, 12 tails. What is the experimental probability for flipping a tail? If Mark & John flip the coin 100 times, what do you think will happen to the experimental probability?
Homework
31) Bart makes 20% of his free throws. If he takes 500 free throws, how many go in the basket? Predict how many baskets Bart makes when he takes 25 free throws.
32) A factory produces 1000 light bulbs per minute. Each minute, one bulb produced will be defective. What is the theoretical probability of selecting the defective bulb from the light bulbs produced in one minute? What is the theoretical probability of selecting a defective bulb from the light bulbs produced in one hour?
33) Every 100th box of candy contains a prize. What is the theoretical probability for selecting the box of candy with a prize? A case contains 1000 boxes and how many prizes? What is the probability of selecting a box containing a prize from a case?
34) Create a situation where the experimental probability is greater than the theoretical probability.
35) How does understanding probability help someone who plays cards?
Probability of Compound Events
Classwork
36) You are given a pair of dice. One die is numbered 1 through 6 but the other die is numbered 7 through 12. What are the odds of rolling a 3 and an 8?
37) A machine generates numbers randomly from balls numbered 5 through 15. Two numbers are selected, with replacement. What are the odds that both the numbers picked will be 8?
38) A bag with 6 blue marbles, 3 green marbles, and 4 orange marbles is lying on a table. What is the probability that John will pick 2 green marbles? (without replacement)
39) What is the probability that the first three cards drawn from a full deck of cards are clubs? (without replacement)
40) There are 6 male puppies and 3 female puppies. What is the probability that the first two puppies chosen will be males? (without replacement)
Homework
41) What is the probability that the first three cards drawn from a full deck of cards are kings?
42) You dropped two coins. What is the probability that they will both land on heads?
43) Bill Gates wrote a computer program that generates three random numbers between 1 and 10. What is the probability that all three values will be three?
44) A lottery machine generates numbers randomly. Three numbers are picked between 1 and 20. What is the probability that all three numbers that are picked are 17?
45) There are 4 blue marbles and 2 red marbles. A marble is selected and not returned. What is the probability that two red marbles will be chosen?
Measures of Center
Classwork
Use the stem-and-leaf plot to answer the following questions.
Stem / Leaf1 / 0 0 1
2 / 4 5 7
3 / 2
Key 1 / 2 = 12
46) What is the mean?
47) What is the median?
48) What is the mode?
49) Which measure of center best describes the data set? Explain.
Homework
Use the stem-and-leaf plot to answer the following questions.
Stem / Leaf4 / 5 5
5
6 / 2 2 5 6
Key 1 / 2 = 1.2
50) What is the mean?
51) What is the median?
52) What is the mode?
53) Which measure of center best describes the data set? Explain.
Measures of Variation
Classwork
Use the data set to answer the following questions.
6, 6, 8, 2, 3, 2, 5, 0, 1, 2, 3
54) What is the median?
55) What is the lower quartile?
56) What is the upper quartile?
57) What is the least value?
58) What is the greatest value?
59) What is the interquartile range?
60) What is the range?
Homework
Use the data set to answer the following questions.
12, 21, 15, 12, 27, 22, 19, 19, 20, 23
61) What is the median?
62) What is the lower quartile?
63) What is the upper quartile?
64) What is the least value?
65) What is the greatest value?
66) What is the interquartile range?
67) What is the range?
Mean Absolute Deviation
Classwork
Use the following data to answer the next set of questions. Round your answers to the nearest hundredth.
Number of Students per Class at the Local Community College
x
x x
x x x x
x x x x x x x
30 31 32 33 34 35 36 37 38 39 40
Number of Students per Class at the State College
x x
x x x x
x x x x x x
x x x x x x x x
30 31 32 33 34 35 36 37 38 39 40
68) What is the mean number of students per class at the local community college?
69) What is the mean number of students per class at the state college?
70) What is the difference of the means?
71) What is the mean absolute deviation of the data set for the local community college?
72) What is the mean absolute deviation of the data set for the state college?
73) Which college has more variability in the number of students it has per class? Explain your answer.
Homework
Use the following data to answer the next set of questions. Round your answers to the nearest hundredth.
Points Earned per Game for the Timberwolves
x
x
x x x
x x x x
x x x x x x x
0 1 2 3 4 5 6 7 8 9 10
Points Earned per Game for the Little Giants
x
x x x
x x x x x
x x x x x x x
0 1 2 3 4 5 6 7 8 9 10
74) What is the mean number of points earned by the Timberwolves per game?
75) What is the mean number of points earned by the Little Giants per game?
76) What is the difference of the means?
77) What is the mean absolute deviation of the data set for the Timberwolves?
78) What is the mean absolute deviation of the data set for the Little Giants?
79) Which team has more variability in the number of points it earns per game? Explain your answer.
Probability Unit Review
Multiple Choice – Choose the correct answer for each question.
1) A bag contains 12 red marbles, 4 black marbles, 4 purple marbles and 2 pink marbles. What is the probability of selecting a black marble?
NJ Center for Teaching and Learning ~ 10 ~ www.njctl.org
a.
b.
c. 4
d.
NJ Center for Teaching and Learning ~ 10 ~ www.njctl.org
NJ Center for Teaching and Learning ~ 10 ~ www.njctl.org
2) A bag contains 12 red marbles, 4 black marbles, 4 purple marbles and 2 pink marbles. What is the probability of selecting a white marble?
NJ Center for Teaching and Learning ~ 14 ~ www.njctl.org
a. b. 1 c. 0 d.
3) A die is rolled 8 times and a “5” is rolled three times. What is the experimental probability for rolling a 5?
NJ Center for Teaching and Learning ~ 14 ~ www.njctl.org