Practice Population vs Sample in Math
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
A population is the entire group you want to study. A sample is a smaller subset of that population that you actually collect data from.
You cannot taste every cookie in the bakery to check quality โ you taste a few (sample) and draw conclusions about the whole batch (population).
Showing a random 20 of 50 problems.
Example 1
easyA scientist wants to know the average weight of all redwood trees in California. She measures 80 trees. What is the population?
Example 2
easyA researcher studies all 500 students in a school by surveying 50 of them. What are the 50?
Example 3
mediumWhy does a larger random sample usually give a better estimate?
Example 4
mediumA magazine surveys readers via mail; 8% respond. Why is the resulting sample likely biased?
Example 5
easyTrue or false: the sample is always smaller than the population.
Example 6
hardA random sample gives . A second random sample from the same population gives . Why aren't they equal?
Example 7
mediumA city has 40% homeowners. A truly representative sample of 250 residents should contain about how many homeowners?
Example 8
mediumA census measures EVERY person in a country. Is that a sample or the population?
Example 9
easyYou ask 30 customers at a coffee shop their favorite drink. What is the sample size?
Example 10
mediumA college has 12,000 students. A survey of 400 finds 62% own a car. Which number is the parameter and which is the statistic?
Example 11
mediumA magazine's online poll gets 8,000 responses. What kind of sample is this likely to be?
Example 12
mediumWhich is better: a random sample of 100 or a biased sample of 1000?
Example 13
easyYou read every page of a 300-page book to count words on each. Sample or population?
Example 14
mediumA national poll calls 1,000 random adults. What is the population, and what is the sample size?
Example 15
mediumA sample mean is and the population mean is . The difference is called what?
Example 16
hardYou want the population mean weekly screen time of US teens. You only have data on 12 of your cousins. List two reasons this sample is poor.
Example 17
mediumIn a sample of 50, the mean test score is 78. Does this prove the population mean is 78?
Example 18
challengeYou want to generalize to ALL teens but sample only a coding-camp. What's the threat to validity?
Example 19
easyWhich symbol denotes a sample mean?
Example 20
easyA value describing the whole population (like the true mean) is called a what?