Population Inferences Worksheets Grade 7

1. Lily is a biologist studying fish in a lake. She catches a random sample of 83 fish, tags them, and releases them. Later, she catches another random sample of 120 fish and finds that 40 of them have tags. Estimate the total number of fish in the lake.
2. A random sample of 150 students from a middle school shows that 96 students prefer pizza over burgers. If the school has 1,250 students, estimate the number of students who prefer pizza.
3. A wildlife conservation team is tracking the population of monarch butterflies in a nature preserve. They tagged 120 butterflies in the spring. During their summer survey, they captured 200 butterflies and found that 30 of them had tags. Based on this capture-recapture data, what is the estimated total population of monarch butterflies in the preserve?

…and 4 more problems

1. Charlotte surveys a random sample of 150 students at her school and finds that 96 of them prefer pizza over tacos for lunch. If the school has 1,250 students, estimate the number of students who prefer pizza over tacos.
2. A random sample of 240 students from a large school shows that 156 students prefer digital textbooks over printed ones. Based on this sample, what is the estimated number of students in the entire school of 1200 students who prefer digital textbooks?
3. (-4)³ + 2 × (18 - 5)² ÷ 13 = ?

…and 5 more problems

1. A school district is conducting a survey about student transportation methods. They randomly select 250 students from a total population of 12,500 students. The survey finds that 40% of the sampled students walk to school. Based on this sample, approximately how many students in the entire district would you expect to walk to school?
2. A random sample of 135 students from a large school shows that 81 prefer digital textbooks over print. Estimate the number of students in the entire school of 1125 who prefer digital textbooks.
3. Liam surveys a random sample of 45 students at his school about whether they prefer reading physical books or e-books. In the sample, 27 students prefer physical books. Liam's school has a total of 765 students. The bar graph below shows the sample results, with a blue bar for physical books (height 27) and a green bar for e-books (height 18). Based on this random sample, estimate how many students in the entire school prefer physical books, and explain why your estimate is reasonable.

…and 4 more problems