Reason About Random Samples

Aaliyah wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy

• thirty students who are rarely tardy

• thirty of her friends

• thirty randomly selected students at school

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected. 

• systematic

• random sample

• convenience

• biased sampling

Why do we randomly select our samples?

• for control

• reduce bias

• so we don't get the same answers from everyone

• to eliminate confounding results

_________ is a sample in which each individual or object in the entire population has an equal chance of being selected.

• Biased Sample

• Population

• Random Sample

• Quartile

Select all that apply!

• A

• B

• C

• D

• E

A travel club has 3,000 members. A random sample of 50 of the club members found that 12 people like mountain vacations best. Which statement is NOT supported by the sample data?

• Twenty-four percent of those sampled say they like mountain vacations best.

• An estimated 720 club members would likely say they enjoy mountain vacations best.

• Almost one-quarter of club members would likely say they enjoy mountain vacations best.

• More than 2,500 club members would likely say they prefer other vacations over mountain vacations.

• Sample A

• Sample B

• Sample C

Lana and Jeff each randomly surveyed 15 students about their favorite types of movies. What would you expect to see in the samples? Select all that apply.

• Different members are found in each sample.

• Some members may possibly overlap in each sample.

• Each sample gave the same responses.

• Both samples could be representative of the population.

• Both samples include only Lana and Jeff's friends.

The table shows the results of a random survey taken at an amusement park in which they asked guests that had previously visited the park before, to name their favorite ride. Based upon the results of this survey, what inference can you make about the entire population of visitors at the amusement park that day?

• The Green Dragon is the least popular ride.

• The King Canyon was exactly twice as popular as the Monte Carlo.

• The Ellipse is the most popular ride, with more than half of those surveyed choosing it as their favorite ride.

• One-third as many people chose the Monte Carlo as chose The Green Dragon.

A principal randomly chooses 40 students from grade 5. Of these students, 9 were wearing watches. Based on this information, what is the most reasonable prediction of the number of students wearing watches in a group of 120 students?

• 27

• 9

• 18

• 80