Comparing Two Random Samples

The dot plots show the weights of a random sample of fish from two lakes. Pick the statement that describes the variability of the samples.

• The variability of the weights of the fish in Lake S is greater than the variability of the weights of the fish in Lake R.

• The variability of the weights of the fish in the two lakes are about the same.

• The variability of the weights of the fish in Lake R is greater than the variability of the weights of the fish in Lake S.

• You cannot determine variability based on a dot plot.

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.

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: "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)

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.

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)

Choose the best sample.

• Sample A

• Sample B