Population, Samples, and Center Variation

Compare the data using the measures of center (median) and variation (interquartile range). Select all correct statements.

• The median of City A (3 inches) is much lower than the median of City B (6 inches).

• The IQR of City A is 4. The IQR of City B is also 4.

• City A generally gets less snow than City B, but their variation is the same.

• City B has a greater variation than City A.

In the previous question, you predicted how many students on your team would have a March birthday. Is your prediction valid? Why or why not?

• Yes, it is valid. The sample is representative of the population, selected at random, and large enough to provide accurate data.

• Yes, it is valid. The students in social studies are more likely to answer honestly.

• No, it is not valid. 30 students is not a big enough sample.

• No, it is not valid. People born in March are less likely to take Social Studies.

Express the difference in the measures of center (median) as a multiple of each measure of variation (IQR from City A and IQR from City B).

• The difference in the measures of center as a multiple of each measure of variation is 0.75 (since both have the same IQR).

• The difference in the measures of center as a multiple of each measure of variation is 1.33 (since both have the same IQR).

• The difference in the measures of center as a multiple of each measure of variation are 0.75 and 1.33.

In the last problem, you should have found that the mean is 189. Now find the mean absolute deviation (MAD) of the data. Round your answer to the nearest tenth.

Choose the true statement(s) about the census and sample shown.

• The sample could be considered too small.

• The sample is biased because is does not include everyone.

• The sample is representative of the population's sub-groups.

A survey company was trying to see if people in a state thought the pollution was too high. Which choice best represents a population?

• Every person in the state

• A selection of people from each neighborhood in the state

• A selection of people who live near the highways

• A selection of people who live in small towns

7.SP.1

• A

• B

• C

• D

• Representative Sample

• Voluntary Sample

• Random Sample

• Systematic Sample

Would the mean or the median be the better measure of center to describe the data?

• median, because there are gaps and/or clusters

• mean, because the data is symmetric and equally spread along the number line

Identify the population and sample for each example.

• Population: Students

  Sample: Members of the football team

• Population: Members of the football team

  Sample: Students

• Population: Students

  Sample: Students that have had a broken bone

• Population: Members of the football team

  Sample: Members of the football team that have broken a bone.