Predicting Probabilities

In a random survey of 50 students at Great Middle School, 32 said chocolate was their favorite flavor of yogurt. The school has 450 students. How many of them are likely to select chocolate as their favorite flavor? 

• 144

• 162

• 225

• 288

Tags

CCSS.7.RP.A.3

The sections of spinner below are shaded red, blue, or green. Out of 24 spins, how many times will the spinner land on blue or green? 

• 16

• 20

• 12

• 6

There are 25 counters in a bag: 6 red,
4 white, 7 blue, and 8 yellow. You choose one counter at random. Which color are you least likely to choose? 

• white 

• blue 

• red 

• yellow

A bag contains:-5 red marbles-6 blue marbles-3 green marbles-4 black marbles-2 yellow marbles
A marble will be drawn from the bag and replaced 100 times. What is a reasonable prediction for the number of times a green or black marble will be drawn?

• 14

• 65

• 7

• 35

• 100
• 150
• 200
• 250

In a certain population of birds, about 40 percent of the birds have a wingspan greater than 10 inches. Biologists studying the birds will create a simulation with random numbers to estimate the probability of finding 1 bird in a sample of 6 birds with a wingspan greater than 10 inches. Which of the following assignments of the digits 0 to 9 will model the population?

• Let the even digits represent birds with a wingspan greater than 10 inches and the odd digits represent birds with a wingspan less than or equal to 10 inches.

• Let the digits 0 and 1 represent birds with a wingspan greater than 10 inches and the remaining digits represent birds with a wingspan less than or equal to 10 inches.

• Let the digits from 0 to 2 represent birds with a wingspan greater than 10 inches and the remaining digits represent birds with a wingspan less than or equal to 10 inches.

• Let the digits from 0 to 3 represent birds with a wingspan greater than 10 inches and the remaining digits represent birds with a wingspan less than or equal to 10 inches.

• Let the digits from 0 to 4 represent birds with a wingspan greater than 10 inches and the remaining digits represent birds with a wingspan less than or equal to 10 inches.

A principal randomly chose 40 students from grade 5. Of these students, 9 were wearing watches. Based on this information, what is the most reasonable prediction of the number of students wearing watches in a group of 120 students from grade 5?

• 27

• 9

• 18

• 80

Tags

CCSS.7.RP.A.3

Four colors of blocks are placed in a bag and each time a block is chosen from the bag, its color is written down in the table and the placed back in the bag.  The experiment is conducted 75 times.  Which color has an experimental probability of 1/3?

• green

• blue

• yellow

• red

An ice-skating rink inspects 25 pairs of skates and finds 2 pairs to be defective.  The rink has 175 pairs of ice skates. Predict the number of pairs that are likely to be defective.

• 14

• 50

• 7

• 65

These 12 shapes are put into a bag.  What is the probablity of reaching into the bag without looking and pulling out a square, NOT replacing the square and pulling out a second square?

• 1/11

• 1/9

• 1/3