Back to Compare center and spread of data sets — Problem 3 · Task Set 2

Exercises: Comparing Center and Spread of Data Sets

Work through each section in order. Report center and spread as matched
pairs: mean travels with standard deviation (SD), median travels with the
interquartile range (IQR). Choose the pair by the SHAPE of the data first:
roughly symmetric uses mean/SD; skewed or outlier-laden uses median/IQR. A
complete comparison of two or more sets states a center finding AND a spread
finding. Round SD to two decimal places unless told otherwise.

Grade 9·21 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-id-a-2

Work through problems with immediate feedback

Fluency Practice

Compute each statistic. Keep mean with SD and median with IQR.

Set $X$ has mean $50$ and SD $4$ . Set $Y$ has mean $50$ and SD $12$ . What can you conclude?

The two sets have the same center, but $Y$ is more spread out (more variable) than $X$ .

$Y$ has larger values than $X$ , because its SD is bigger.

$Y$ is a better data set than $X$ , because a bigger SD is better.

$X$ has a higher center than $Y$ , because its SD is smaller.