Making Predictions Sample Population

The table shows the results of a school survey about favorite frozen yogurt flavors. If there are 432 students in the school, predict how many would select vanilla or strawberry as their favorite flavor.

• 72 students

• 126 students

• 198 students

• 942 students

The table shows the results of a random survey taken at an amusement park in which they asked guests that had previously visited the park before, to name their favorite ride. Based upon the results of this survey, what inference can you make about the entire population of visitors at the amusement park that day?

• The Green Dragon is the least popular ride.

• The King Canyon was exactly twice as popular as the Monte Carlo.

• The Ellipse is the most popular ride, with more than half of those surveyed choosing it as their favorite ride.

• One-third as many people chose the Monte Carlo as chose The Green Dragon.

A principal randomly chooses 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?

• 27

• 9

• 18

• 80

At an assembly 7 out of 10 students who entered the gym were carrying a backpack. Based on this information, if 700 students were at the assembly, how many students could be expected to be carrying a backpack?

• 49

• 490

• 210

• 421

Tags

CCSS.7.RP.A.3

In a random sample of 20 students from a class, 8 students said they participate in after-school sports. Predict the total number of students participating in after-school sports in a school of 400 students.

• 160

• 80

• 120

• 200

Answer explanation

To find the total number of students participating in after-school sports in a school of 400 students, we can use the ratio method. 8 students out of 20 participate, so 8/20 = x/400. Solving for x gives us 160 students.

Tags

CCSS.7.RP.A.3

In a random sample of 60 apples from a farm, 12 apples were found to be rotten. If the farm has 3000 apples, predict the number of rotten apples.

• 600

• 240

• 120

• 480

Answer explanation

To predict the number of rotten apples, use the ratio of rotten apples in the sample to the total apples in the farm: (12/60) * 3000 = 240 rotten apples.

Tags

CCSS.7.RP.A.3

A random sample of 200 people at a concert shows that 120 people are wearing hats. Predict the number of people wearing hats if 800 people are at the concert.

• 480

• 320

• 600

• 400

Answer explanation

To predict the number of people wearing hats for 800 attendees, use the ratio of people wearing hats in the sample. 120/200 = x/800. Solving for x gives 480.

Tags

CCSS.7.RP.A.3

A survey on a random sample of 500 people in a city shows that 250 people use public transportation. Predict the number of people using public transportation if the city's population is 10,000.

• 5000

• 2500

• 7500

• 1000

Answer explanation

To predict the number of people using public transportation in a city with a population of 10,000, we can use the ratio from the sample. 250 people out of 500 use public transportation, so in a population of 10,000, we can expect 5000 people to use public transportation.

Tags

CCSS.7.RP.A.3

The table shows the results of a survey of 200 people attending a hockey game.
The attendance for the hockey game is about 25,000 visitors each game.  Based on the table, how many people out of 25,000 could be expected to buy a pennant?

• 1,375

• 1,650

• 2,750

• 3,850

A random sample of 80 books at a library showed that 32 books were fiction. Predict the total number of fiction books in a library that has 400 books.

• 160

• 200

• 140

• 120

Answer explanation

To find the total number of fiction books in the library, we can set up a proportion: 32 books out of 80 are fiction, so 400 books would have (32/80) * 400 = 160 fiction books.

Tags

CCSS.7.RP.A.3