Measures of Center and Measures of Variation

The double box plot shows the average monthly high temperatures for Phoenix, Arizona, and Las Vegas, Nevada.

• Las Vega temperatures show greater variability than Phoenix.

• Phoenix temperatures show greater variability than Las Vegas.

• Las Vegas temperatures are more consistently centered around the median.

• Phoenix has a greater temperature range than Las Vegas.

The double dot plot shows the number of city pet registrations for several days.

• The mean number of cat registrations is greater than the mean number of dog registrations.

• The dogs’ data has a mean of 10 registrations.

• The cats’ data has a mean of 15 registrations.

• The mean number of dog registrations is greater than the mean number of cat registrations.

The double box plot below shows the number of car shows attended by two car clubs each year. Compare the centers and variations of the two populations.

• The Cruisers' IQR is 5 greater than the Car Hops' IQR.

• The Car Hops' IQR is 2 greater than the Cruisers' IQR.

• The data for the Car Hops is more consistent.

• The data for the Cruisers is more consistent.

The double box plot below shows the results of a school survey about types of lunch purchased.

• The a la carte data have less variation than full lunch.

• The a la carte data are centered around a higher value.

• The data for full lunch has a median of 180.

• The data for a la carte lunches has an interquartile range of 240 students.

The double box plot shows the number of Calories per serving for various fruits and vegetables.

• The median for the fruit data is 125.

• The median for the vegetable data is 75.

• The fruits have a higher number of calories with a greater variation.

• The vegetables have a higher number of calories with a greater variation.

The double dot plot shows the gas mileage, in miles per gallon, for several cars and SUVs.

• The cars have a greater gas mileage with a greater variation.

• The cars have a greater gas mileage with a less variation.

• SUVs have less gas mileage with greater variation.

• SUVs are centered around a greater median.

The double plot shows the daily attendance for two fitness clubs for one month.

• Fun Fit has greater attendance with greater variation.

• Greg's Gym has greater attendance with greater variation.

• Fun Fit has greater attendance with less variation.

• Greg’s Gym has a greater attendance with less variation.

The double dot plot shows the number of minutes two students spent practicing the piano.

• Both data sets have the same variation, but Lily’s data centers around a higher value.

• Both data sets have the same variation, but Alessandra's data centers around a higher value.

• Generally, Lily practiced less minutes than Alessandra.

• Generally, Alessandra practiced more minutes than Lily.

The double box plot shows the daily number of customers for two ice cream parlors.

• The Corner Creamery’s data centers around 80 customers with an interquartile range of 35 customers.

• Sue’s Ice Cream data centers around 60 customers with an interquartile range of 20 customers.

• Sue's Ice Cream has a greater number of daily customers.

• Sue’s Ice Cream has a greater consistency in its distribution.

Ms. Andrey claims the average score on a quiz in her class was 25. Mr. Luna claims the average score on a quiz in his class is 25.

• Ms. Andrey used the mode, while Mr. Luna used the median.

• Ms. Andrey used the mean, while Mr. Luna used the mode.

• Both teachers used the mean.

• Both teachers used the median.