Sample and Inference

Group A and Group B were randomly sampled from the same population. Which statements below are true? Select all that apply.

• Group A has a greater median than Group B

• Group A has a greater range than Group B

• Group A has greater variability than Group B

• Group B has a greater median than Group A

• You cannot tell which group has the greater median based on the picture.

Keyli gathers the heights of a random sample of six graders and seventh graders and displays the data in box plots. What can she say about the data sets?

• The 6th grade sample has greater variability.

• The 7th grade sample has greater variability.

• The 6th grade sample has the greater median.

• The ranges are equal for both samples.

Which data set shows students who tend to spend more time on homework per week?

• Finn's Data Set

• Jonah's Data Set

Mr. Jackson had students grow the same type of plant in two different rooms to test the growing conditions. The results are shown in the box plant. Choose ALL accurate statements below.

• Room 7G has the tallest plant.

• 75% of 7D plants are 8 in. or taller.

• 7G has a greater median height.

• Room 7D has the shortest and tallest plants.

Population or Sample? A quality control engineer is curious about the thickness of paint on a car at her factory. She randomly selects 30 points on the car and measures the paint thickness at each of those points.

• Population

• Sample

There are 45 people working in a particular building. A survey on dietary habits is conducted by giving every third person in the building a questionnaire to fill out. From the questionnaire, the researcher obtains a score on the dietary habits of the 15 people.

What is the number of members in the population?

Mathematical Equivalence

ON

Kerron gathers the heights of a random sample of 6th graders and 7th graders and displays the data in box plots. Which statement below is true?

• The median of the 7th grade sample is greater than the 6th grade sample.

• The 7th grade sample has greater variability.

• The ranges of both data samples are equivalent.

• The median of the 6th grade sample is greater than the 7th grade sample.

Mykel surveyed 15 7th graders and 15 8th graders at his school to see how many hours they spend per day listening to music. He made two box plots to compare the data sets. What inference can he draw from the data sets?

• The range is greater for the 8th graders, so there is greater variability for the 8th graders than the 7th graders.

• The person who listens to music the least is a 7th grader.

• The median is greater for the 7th graders, so they generally spend more time listening to music than 8th graders.

• No inferences can be made from the box plots.

A random survey of seventh- and eighth-grade students was conducted to find out how many hours are spent doing homework each night. Of the two sets of data, which has the greater median?

• Seventh graders

• Eighth graders

• They have the same median.

• Impossible to determine from the box plot.

Maria collects data from a random sample of 7th graders in her school and finds that 16 out of 20 7th graders participate in after-school activities. How many students should Maria expect to participate in after-school activities if 240 total 7th graders attend Maria's school? Write the numerical answer only.