Making Inferences About Populations Using Proportions

A manager samples receipts of every fifth person in line. Out of 50 people, 4 had a mispriced item. If 600 people go to the store each day, how many can you expect to have a mispriced item?

• 50 people

• 80 people

• 48 people

• 12 people

Jenny randomly selects 20 boxes of crayons from the shelf and finds two boxes with at least one broken crayon. If the shelf holds 130 boxes, how many would you expect to have at least one broken crayon?

• 10 boxes

• 13 boxes

• 6.5 boxes

• 2 boxes

A middle school has 490 students. Mae surveys a random sample of 60 students and finds that 24 of them have dogs. How many students are likely to have dogs?

• 8 students

• 40 students

• 192 students

• 196 students

Part of the population of 10,800 hawks at a national park are building nests. A random sample of 72 hawks shows that 12 hawks are building nests. Estimate the number of hawks building a nest in the population.

• 1,800 hawks

• 150 hawks

• 432 hawks

• 10,800 hawks

A random sample of dogs at different animal shelters shows that 12 of 60 dogs are puppies. The cities shelters collectively house 1,200 dogs each year. Estimate how many are puppies.

• 50 puppies

• 240 puppies

• 20 puppies

• 600 puppies

There are 600 students at Hilda’s school. Out of 30 students she surveys, 8 of them ride their bikes to school. Estimate how many students ride their bikes to school from the population.

• 160 students

• 20 students

• 74 students

• 240 students

A manufacturer fills an order for 4,200 smart phones. The quality inspector selects a random sample of 60 phones and finds that 4 are defective. How many smart phones in the order are likely to be defective?

• 70 smart phones

• 900 smart phones

• 1,050 smart phones

• 280 smart phones

Part of the population of 4,500 elk at a wildlife preserve is infected with a parasite. A random sample of 50 elk shows that 8 of them are infected. How many elk are likely to be infected?

• 720 elk

• 400 elk

• 90 elk

• 562.5 elk

A random sample of 120 ticket buyers is surveyed, and 28 buyers made their purchase on the first day tickets were being sold. How many of the 4,200 total tickets are likely to have been purchased on the first day they were available?

• 150 tickets

• 35 tickets

• 980 tickets

• 233 tickets

A store manager selects 30 cartons of eggs and finds 4 cartons that have cracked eggs. If the store has 105 cartons of eggs, how many cartons can she expect to have cracked eggs in them?

• 15 cartons

• 7.5 cartons

• 26 cartons

• 14 cartons