Sampling & Inference Worksheets Grade 11

1. Sophia is analyzing a triangular plot of land with sides measuring 17 meters, 21 meters, and 24 meters. She needs to find the area of this triangle. What is the area in square meters?
2. Olivia is conducting a survey about high school students' screen time habits. She stands outside the school library and asks every 5th student who enters to complete her survey. Out of 850 students at the school, she collects 85 responses. What percentage of the student population is represented in Olivia's sample?
3. Olivia is studying smartphone ownership patterns in her city. She stands outside a popular electronics store and surveys 200 people about whether they own a smartphone. She finds that 185 out of 200 people surveyed own a smartphone. If the actual smartphone ownership rate in the city is 75%, how many people in Olivia's sample would be expected to own a smartphone if her sampling method were unbiased?

…and 3 more problems

1. Emma is studying smartphone usage patterns at her high school. She stands outside the main entrance and surveys the first 75 students who arrive. If the school has 1500 students total, what percentage of the student population did Emma sample?
2. Ava is studying geometric patterns and creates a sequence of nested squares. The largest square has side length 16 cm. Each subsequent square is inscribed by connecting the midpoints of the previous square's sides, creating a smaller rotated square inside. If this process continues infinitely, what is the total area of all the squares combined?
3. Sophia is conducting a survey about smartphone usage patterns among high school students. She stands outside the school library and asks every 10th student who enters to complete her survey. Out of 850 students at the school, she collects 72 responses. What percentage of the total student population is represented in Sophia's sample?

…and 3 more problems

1. Mason is conducting a survey about high school students' study habits. He randomly selects 120 students from the 1500 students at his school and finds that 78 of them use a specific study app. Based on this sample, what is the estimated number of students in the entire school who use this study app?
2. Aroha is conducting a study about student opinions on school start times. She stands outside the school library and surveys every 10th student who enters. Out of 950 students at the school, she surveys 95 students. 76 of them support later start times. What percentage of Aroha's sample supported later start times?
3. Aroha is studying the arrangement of stones in a sacred Maori pattern. The pattern consists of 7 concentric circles of stones. The innermost circle has 3 stones, and each subsequent circle has 5 more stones than the previous circle. How many stones are in the outermost circle?

…and 3 more problems