Population Inferences Worksheets Grade 7

1. A city is planning a new park and wants to know what percentage of residents would prefer a swimming pool over a skate park. They survey a random sample of 12,500 residents and find that 7,800 prefer a swimming pool. Based on this sample, how many residents out of the city's total population of 150,000 would be expected to prefer a swimming pool?
2. A town has 12,000 residents. Mason surveys a random sample of 250 residents and asks them whether they support building a new community center. In the sample, 127 say yes. Based on this random sample, estimate the number of residents in the entire town who support the new community center. Explain your reasoning.
3. 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.

…and 4 more problems

1. A wildlife conservation team is studying the population of deer in a large forest preserve. They capture and tag 150 deer in the spring. During their summer survey, they capture 200 deer and find that 25 of them have tags. Based on this capture-recapture data, what is the estimated total deer population in the preserve?
2. Maya is a biologist studying fish in a lake. She catches a random sample of 80 fish, tags them, and releases them. Later, she catches another random sample of 51 fish and finds that 20 of them have tags. Estimate the total number of fish in the lake.
3. Mere is investigating whether students at her school prefer playing basketball or netball. She surveys a random sample of 40 students. In her sample, 25 students say they prefer basketball. If there are 720 students in the whole school, about how many students would you expect to prefer basketball? Use a bar graph to support your reasoning: imagine a bar graph where the bar for basketball reaches 25 out of 40 on the vertical axis, and the bar for netball reaches 15 out of 40. Based on this visual sample data, what is the best estimate for the number of students in the entire school who prefer basketball?

…and 4 more problems

1. Charlotte wants to estimate how many of the 14,400 residents in her town support building a new skate park. She randomly selects 240 residents and asks them. Her results are shown in a bar graph: a blue bar for 'Support' reaches a height of 84, and a red bar for 'Do Not Support' reaches a height of 156. Based on this random sample, estimate the number of residents in the entire town who support the new skate park.
2. 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.
3. Zoe caught and tagged 50 fish in a lake. Two weeks later, Zoe caught a random sample of 83 fish and found that 25 of them were tagged. Estimate the total number of fish in the lake.

…and 4 more problems