Comparing Data Displays and Distributions

For which of the following would it be inappropriate to display the data with a single pie chart?

• The distribution of car colors for vehicles purchased in the last month.

• The distribution of unemployment percentages for each of the 50 states.

• The distribution of favorite sport for a sample of 30 middle school students.

• The distribution of shoe type worn by shoppers at a local mall.

The following bar graph shows the distribution of favorite subject for a sample of 1000 students. What is the most serious problem with the graph?

• This distribution should be displayed with a pie chart

• The vertical axis should show the percent of students.

• The vertical axis should start at 0 rather than 100

• The subjects are not listed in the correct order.

In the 2010–2011 season, the Dallas Mavericks won the NBA championship. The two-way table below displays the relationship between the outcome of each game in the regular season and whether the Mavericks scored at least 100 points.

Which of the following is the best evidence that there is an association between the outcome of a game and whether or not the Mavericks scored at least 100 points?

• The Mavericks won 57 games and lost only 25 games.

• The Mavericks scored at least 100 points in 47 games and

  fewer than 100 points in only 35 games.

• The Mavericks won 43 games when scoring at least 100 points and only 14 games when scoring fewer than 100 points.

• The Mavericks won a higher proportion of games when scoring at least 100 points (43/47) than when they scored fewer than 100 points (14/35).

If there is no association between gender and handedness for the members of the sample, which of the following is the correct value of x?

• 10

• 20

• 36

• 45

Here are the amounts of money (cents) in coins carried by 10 students in a statistics class: 50, 35, 0, 97, 76, 0, 0, 87, 23, 65. To make a stem plot of these data, you would use stems

• 0, 2, 3, 5, 6, 7, 8, 9.

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

• 0, 3, 5, 6, 7.

• 00, 10, 20, 30, 40, 50, 60, 70, 80, 90.

The histogram below shows the heights of 300 randomly selected high school students. Which of the following is the best description of the shape of the distribution of heights?

• Roughly symmetric and unimodal

• Roughly symmetric and bimodal

• Roughly symmetric and multimodal

• Skewed to the left

The following histogram shows the distribution of the percent of women aged 15 and over who have never married in each of the 50 states and the District of Columbia. Which of the following statements about the histogram is correct?

• The center of the distribution is about 36%.

• There are more states with percent above 32 than there are states with percent less than 24.

• About half of the states had percent between 24% and 28%

• There was one state with a value of exactly 33%.

When comparing two distributions, it would be best to use relative frequency histograms rather than frequency histograms when

• the distributions have different shapes.

• the distributions have different spreads.

• the distributions have different centers.

• the distributions have different numbers of observations.

Which of the following is the best reason for choosing a stem plot rather than a histogram to display the distribution of a quantitative variable?

• Stem plots allow you to split stems; histograms don’t.

• Stem plots allow you to see the values of individual observations.

• Stem plots are better for displaying very large sets of data.

• Stem plots make it easier to determine the shape of a distribution.

The scores on a statistics test had a mean of 81 and a standard deviation of 9. One student was absent on the test day, and his score wasn’t included in the calculation. If his score of 84 was added to the distribution of scores, what would happen to the mean and standard deviation?

• Mean will increase, and standard deviation will increase.

• Mean will increase, and standard deviation will decrease.

• Mean will increase, and standard deviation will stay the same.

• Mean will decrease, and standard deviation will increase.