Best Measure of Center and Variability and Data Distribution

Gabriella’s quiz grades are shown below.
88, 92, 92, 96, 98
Gabriella scored a 20 on her sixth quiz. What effect does this score have?

• The low score causes the median to increase.

• The low score causes the median to decrease.

• The low score causes the mean to increase.

• The low score causes the mean to decrease.

The data below represent the ages of several people in a class.What effect does Mr. Smith’s age have on the data set?

• Mr. Smith’s age increases the mode of the data.

• Mr. Smith’s age decreases the mean of the data.

• Mr. Smith’s age increases the mean of the data.

• Mr. Smith’s age increases the median of the data.

The boxplots display the distributions of homework time (in hours/week) of a sample of 8^th graders (year 8) and seniors (year 12).

True or false: Students in year 12 typically spent more time on homework than students in year 8.

• True

• False

When the data distribution is symmetric, which is the better measure of variability?

• Mean

• Median

• Mode

• Standard Deviation

• Interquartile Range

Which car club has the higher median?

• Cruisers

• Car Hops

• Their medians are the same

• You can not tell from the box plots

The median is the...

• average of all data values

• the most frequently occurring number

• the difference between the biggest and smallest value

• the middle value

Which data set shows a greater spread (larger IQR)?

• Chess Club

• Checkers Club

• They have the same spread.

• You cannot tell from the box plots.

Here are the times (in minutes) that six students needed to finish a quiz: 10, 14, 15, 15, 14, 10 The standard deviation for this data is 2. A seventh student took 8 minutes to finish the quiz. We added his time to our data. What will happen to the standard deviation?

• It will decrease because our range is bigger.

• It will increase because our range is bigger.

• It will not change.

• It will decrease because we have more numbers in our data set.

A distribution whose dot plot or histogram takes the form of a bell with most of the data clustered near the center and fewer points farther from the center

• Bell-Shaped Distribution

• Bimodal Distribution

• Skewed Distribution

• Uniform Distribution

The given distribution is skewed left. Compare the median and the mean.

• The median and the mean are the same because they both are measures of center

• The median is less than the mean since the distribution is skewed left.

• The median is greater than the mean since the distribution is skewed left.

• There is not enough information to compare the median and the mean.