Unit 8 Quiz 3

Determine if the following scenario represents a random sampling. Choose Yes if it does, and No if it does not. Select the answer with the correct justification. A researcher selects 10 random participants from each of 5 different age groups to study their dietary habits.

• No. Although participants were randomly selected, selecting only 10 from each group may not provide a representative sample.

• No. Even with random selection, at least 50% of participants from each group should be included.

• Yes. The participants were randomly selected, and 10 is a sufficient number for each age group.

Based on the survey, which dinner main course was the least popular?

• Chicken

• Steak

• Vegetarian

Find the relative frequency of the survey outcome. Chicken: ____

• 41.2%

• 37.2%

• 39.2%

• 33.2%

Find the relative frequency of the survey outcome. Vegetarian: ____

• 26%

• 32.8%

• 28%

• 20.8%

How does a larger sample size affect the strength of inferences about the population?

• A larger sample decreases the weakness of inferences about the population.

• A larger sample decreases the strength of inferences about the population.

• A larger sample increases the strength of inferences about the population.

• A larger sample increases the weakness of inferences about the population.

How strong is the size of the sample?

• The sample size is 500 out of 1,500, or 33 1/3% of the entire population. The size of the sample is considered fairly weak to strong for a larger population of 1,500.

• The sample size is 500 out of 1,500, or 33 1/3% of the entire population. The size of the sample is considered fairly weak to weak for a smaller population of 1,500.

• The sample size is 500 out of 1,500, or 33 1/3% of the entire population. The size of the sample is considered fairly strong to strong for a smaller population of 1,500.

Use proportions to determine how many of the 1,500 employees the corporation expects will prefer vegetarian dinner based on the survey.

• Vegetarian: 642 dinners

• Vegetarian: 681 dinners

• Vegetarian: 588 dinners

• Vegetarian: 420 dinners

Use the dot plot to answer the question. The technology club sponsor wanted to know how many field trips the club students went on last school year. If the number of students who went on 3 field trips increased to 8, how many total students should the sponsor expect to keep the number of students who went on 3 field trips proportional to the total number of students? Set up, solve, and explain a proportion.

• A) 48 students; increasing from 5 to 8 students means that there must be 48 total students to keep the ratio constant.

• B) 90 students; increasing by 8 students makes 12 students taking 3 field trips. For the ratio to remain constant, there needs to be 90 total students.

• C) 60 students; because the total number of students should increase to 60 to keep the ratio constant.

If Ronnie's aunt observes 1,400 birds, how many birds would she expect to see on Tuesday? Use a proportion to answer each question.

• 700

• 200

• 300

• 500

If Ronnie's aunt observes 1,400 birds, how many birds would she expect to see on Wednesday? Use a proportion to answer each question.

• 500

• 300

• 700

• 200