7th Grade Statistics and Probability

Probability I

100

Which of the following events has the greatest theoretical probability?

a. Tossing a 5 on the number cube labeled 1-6.

b. tossing a penny and having it land tails up.

c. Spinning a 7 on a spinner with 5 sections labeled 2, 4 , 6, 8, and 10.

d. Pulling a green ribbon randomly from a bag  with 1 red, 1 yellow, and 3 green ribbons. 

d. Pulling a green ribbon randomly from a bag with 1 red, 1 yellow, and 3 green ribbons. 

200

A spinner has three equal sections. The following tables gives the results of 60 spins on the spinner. 

outcome           frequency

blues                      25

red                         18

yellow                     17

How much greater is the experimental probability of landing on blue than the theorectical probability of landing on blue?

a. 1/4

b. 1/10

c. 1/12

d. 1/20

c. 1/12

300

The following outcomes gives the results of tossing a number cube 50 times.

2   5   3   6   5   4   6   6   3   1

4   2   2   4   1   6   5   3   3   6

5   3   2   5   4   6   6   1   3   5

3   1   4   4   3   1   2   5   5   2

6   4   1   3   3   2   1   1   3   6

Which of the following is the experimental probability of tossing a 3 expressed as a percent?

a. 11%

b. 17%

C. 20%

d. 22%

c. 20%

400

Mr. Perez designs a probability model to help him predict which color car high customers will want to buy. He puts equal numbers of red, black, white, gray, and blue slips of paper into a bag to represent all the different possible car colors. Which of the following statements about the model are true?

a. Mr. Perez will most likely not pull any black slips.

b. Mr. Perez is more likely to pull a red slip than a blue slip.

c. Adding another white slip would make this a non-uniform probability model. 

d. The results of Mr. Perez's experiment are likely to exactly match the frequency with which his customers select each color car. 

a. Mr. Perez will most likely not pull any black slips.

500

For each situation, tell whether the situation is unlikely, likely, or neither likely nor unlikely.

a. Drawing a 10 from a bag with 100 slips of paper numbered 1-100.

b. Rolling a number less than 5 on a number cube labeled with the numbers 1-6.

c. Drawing a red marble from a bag containing 8 red and 8 blue marbles. 

a. unlikely

b. likely

c. neither likely nor unlikely

Pobability II

100

Delcon spins a spinner two times with the number 1-4 on it. How many outcomes are possible?

a. 4

b. 8

c. 12

d. 16

d. 16

200

Delcon spins a spinner two times with the number 1-4 on it. 

What is the probability of landing on the number 1 with the first spin and 2 with the second spin?

a. 1/16

b. 1/12

c. 1/8

d. 1/4

a. 1/16

300

Destiny has a bag with 3 green, 4 red, and 5 blue marbles. Destiny will pick 2 marbles form the bag, one at a time without looking. She will not replace a marble before picking the next marble. What is the probability of Destiny picking a red marble, followed by a green marble?

a. 1/12

b. 1/11

c. 7/12

d. 1/2 

b. 1/11

400

A bag hold a number of ribbons as given in the table below. 

color               number of ribbons in bag 

black                              1

blue                               3

green                             4

Jolene pulls a colored ribbon from a bag and does not replace it. She then draws a second ribbon. 

How man outcomes are possible?

a. 5

b. 6

c. 8

d. 9

b. 6

500

A bag hold a number of ribbons as given in the table below.

color number of ribbons in bag

black 1

blue 3

green 4

Jolene pulls a colored ribbon from a bag and does not replace it. She then draws a second ribbon.

What is the probability that Jolene draws two blue ribbons?

a. 3/28

b. 9/64

c. 9/56

d. 6/25

a. 3/28