Samples to Predict Populations

Clementine completes a report by asking 70 students across campus. She found that 48% of KVMS students do not wash their hands after using the bathroom. What is the sample size?

• 48

• 100

• 70

• All KVMS students

A student wants to know which type of pizza the students at his high school prefer. Which option would give a unbiased, representative sample:

• Asking all the students in the hot lunch line.

• Asking 10 random students from each homeroom.

• Asking every other student who gets off a school bus.

• Asking all the 10th graders.

The city council in Middlefield wants to know if residents are in favor of a traffic camera at the main intersection in town. Which example is likely to produce a representative sample?

• Drivers who reside in Middlefield

• Residents randomly chosen from the town register

• All residents of Middlefield

• All people with a five-letter last name

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.

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.

If there are 1,400 customers in a given week, how many would you expect to prefer chocolate strawberry or very berry mix?

• 490 customers

• 55 customers

• 280 customers

• 770 customers

A fitness center asked 80 random patrons how long they exercise on average each day. Results are shown in the table.

If 300 people come to the gym on a given day, approximately how many would you expect to exercise for more than 135 minutes?

• 120 people

• 96 people

• 32 people

• 214 people