Comparing Mean Median

The dot plots show how much time, in minutes, students in a class took to complete each of five different tasks. Select all the dot plots of tasks for which the mean time is approximately equal to the median time.

• Dot plot A

• Dot plot B

• Dot plot C

• Dot plot D

• Dot plot E

Priya asked each of five friends to attempt to throw a ball in a trash can until they succeeded. She recorded the number of unsuccessful attempts made by each friend as: 1, 8, 6, 2, 4. Priya made a mistake: The 8 in the data set should have been 18. How would changing the 8 to 18 affect the mean and median of the data set?

• The mean would decrease and the median would not change.

• The mean would increase and the median would not change.

• The mean would decrease and the median would increase.

• The mean would increase and the median would increase.

Here is a dot plot that shows the ages of teachers at a school. Which of these statements is true of the data set shown in the dot plot?

• The mean is less than the median.

• The mean is approximately equal to the median.

• The mean is greater than the median.

• The mean cannot be determined.

The dot plots show how much time, in minutes, students in a class took to complete each of five different tasks. Select all the dot plots of tasks for which the mean time is approximately equal to the median time.

• A

• B

• C

• D

• E

Coach Lantz recorded the number of shots on goal players made during two weeks of a lacrosse scrimmage. How much greater was week 2's mean than week 1's mean? Type your answer as a one-digit number without a label.

The table shows the finish times of 30 runners in the 100-meter dash. Use the table to identify the inference that can be made by comparing the measures of center.

• Every runner ran faster last year as compared to this year.

• Most runners ran faster last year, on average, as compared to this year.

• The runners ran faster this year, on average, as compared to last year.

• Every runner ran faster this year as compared to last year.

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.

If a data set is skewed, and most of the data are at the lower end of the data, which is a better measure of center? Explain.

• The range; it would be smaller in a skewed data set.

• The mode; it would have to be at the lower end of the data.

• The mean; it is not affected by high or low data in a data set.

• The median; it is less sensitive to outliers in a data set.

Match the following inference with the statistical measure that best justifies the inference: "On average, students in Grade 8 spent 2 more hours last week doing homework than students in Grade 6."

• Mean

• Median

• Range

• Interquartile Range (IQR)

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.