Estimating Averages: Calculating Population Means with Samples

A school has 500 students. A survey is conducted with a sample of 50 students. If the average height of the sample is 150 cm, what is the estimated average height of all students in the school?

• 155 cm

• 145 cm

• 160 cm

• 150 cm

In a city of 10,000 residents, a researcher surveys 200 people about their favorite ice cream flavor. If 60% of the sample prefers chocolate, how many residents likely prefer chocolate?

• 8000

• 4000

• 2000

• 6000

A farmer has a field with 1,200 apple trees. He randomly samples 30 trees and finds that the average number of apples per tree is 150. What is the estimated total number of apples in the field?

• 200000

• 180000

• 150000

• 120000

A library has 2,000 books. A student checks out a sample of 40 books and finds that the average number of pages per book is 300. How many pages are there in all the books in the library?

• 700000

• 500000

• 600000

• 400000

In a town of 5,000 people, a health survey is conducted with a sample of 100 individuals. If the average weight of the sample is 70 kg, what is the estimated average weight of the entire town?

• 70 kg

• 80 kg

• 75 kg

• 65 kg

A company has 1,000 employees. A survey is conducted with a sample of 50 employees. If the average salary of the sample is $50,000, what is the estimated total salary for all employees?

• $50,000,000

• $25,000,000

• $75,000,000

• $1,000,000,000

A teacher wants to know the average score of her class of 30 students. She takes a sample of 10 students and finds their average score is 85. What is the estimated average score for the entire class?

• 85

• 75

• 90

• 80

In a park with 800 trees, a botanist samples 40 trees and finds that the average age of the sampled trees is 20 years. What is the estimated average age of all the trees in the park?

• 30 years

• 20 years

• 15 years

• 25 years

A restaurant has 300 menu items. A food critic samples 15 items and rates them with an average score of 4 out of 5. What is the estimated average score for all menu items?

• 4

• 3

• 5

• 4.5

A city has a population of 15,000. A survey of 150 residents shows that 45% own a pet. How many residents in the city likely own a pet?

• 5000

• 3000

• 6750

• 12000