Comparing Populations

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.

A study is done to compare the fuel efficiency of cars. The first group of cars generally get about 37 miles per gallon. The second group of cars generally get about 37 miles per gallon. Based on the mean values of each​ group, what inference can be​ made?

• The cars in group 2 generally are more fuel efficient.

• The cars in group 1 generally are more fuel efficient.

• The cars in group 1 and group 2 are equally fuel efficient.

• No inferences can be made simply by knowing the mean.

Brazil asks 7 classmates how many erasers and pens they carry in their bags. The mean number of erasers is 10. The mean number of pens is 4. What inference could Brazil make using this data?

• Most of Brazil's classmates carry more pens than erasers in their bags.

• All of Brazil's classmates carry more erasers than pens in their bags.

• Most of Brazil's classmates carry more erasers than pens in their bags.

• Most of Brazil's classmates carry similar amounts of erasers and pens in their bags.

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.

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.

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)