Data With Variability

If you compare the medians of each data set, who spends more time online?

• Seventh graders

• Eight graders

• Both grades spend an equal amount of time online.

• Impossible to determine form the data sets.

One week, Kyasia drove to work. The next week, she rode the train. Each day, she recorded how long it took in minutes. What can Kyasia infer from the two data sets?

• The time it take to get to drive to work is more consistent than the time it takes to take the train.

• Based on the mean, it generally takes longer to take the train to work.

• In terms of time, it is less consistent to drive than it is to take the train to work.

• It's impossible to make any inferences based on the data display.

Match the following inference with the statistical measure that best justifies the inference: "The middle two quartiles of students in Grade 6 had greater variability in time spent doing homework last week than the middle two quartiles of students in Grade 8."

• Mean

• Median

• Range

• Interquartile Range (IQR)

Match the following inference with the statistical measure that best justifies the inference: "The two students in the same grade that had the greatest difference in time spent doing homework last week are in Grade 8."

• Mean

• Median

• Range

• Interquartile Range (IQR)

Match the following inference with the statistical measure that best justifies the inference: "Half of the students in Grade 8 spent more time doing homework last week than at least half of the students in Grade 6."

• Mean

• Median

• Range

• Interquartile Range (IQR)

What do the box plots tell you about the variability of the data?

• B has greater variability because its range and IQR are greater than A.

• B has greater variability because its median & mean are greater than A.

• A has greater variability because its range & IQR are greater than B.

• A has greater variability because its median and mean are greater than B.

Compare the variability of the data for each store.

• The range & IQR are greater at store B as compared to store A.

• There is less variability in prices of DVD players at store A.

• The range & IQR are greater at store A as compared to store B.

• There is more variability in prices of DVD players at store B.

What do the box plots tell you about the growth of a typical plant species?

• B typically grows taller than A since the range for B is greater.

• B typically grows taller than A since the IQR for B is greater.

• A grows taller than B since the median for A is greater.

• A typically grows taller than B since the mean for A is greater.

See the image.

• 15 Students

• 25 Students

• 30 Students

• 50 Students

Compare the measure of center for each of the data sets.

• 90 secDVD players cost less, on average, at Store B

• The range for Store B is greater than the range for store A

• Data for store B has a greater mean, but not greater median than Store A.

• DVD players cost less, on average, at Store A.