AP Stats Quiz 2

The histogram shows the number of minutes needed by  $45$ students to finish playing a computer game. Which of the following statements is correct?

• The distribution is skewed to the right.

• The distribution is skewed to the left.

• The distribution appears to be normal.

• The distribution appears to be chi-square.

• The distribution appears to be uniform. 

As part of a study on the relationship between the use of tanning booths and the occurrence of skin cancer, researchers reviewed the medical records of  $1436$ people. The table summarizes tanning booth use for people in the study who did not and did not have skin cancer.   Of the people in the study who had skin cancer, what fraction used a tanning booth?

•  $\frac{190}{265}$  

•  $\frac{265}{1436}$  

•  $\frac{190}{896}$  

•  $\frac{846}{1436}$  

•  $\frac{190}{1436}$  

Researchers conducted a telephone survey of  $427$  adults living in a large city. The adults were asked whether they planned to purchase a smart watch in the next year. The table shows the responses categorized by the region of the city in which the residents live.  Which of the following graphical displays is most appropriate for comparing the proportions of those surveyed who plan to purchase a smart watch within the four regions ?

• scatterplot

• boxplot

• segmented bar chart
  

• back-to-back stemplot
  

• dotplot

Of the dotplots, which represents the set of data that has the greatest standard deviation ?

• Graph i

• Graph ii

• Graph iii

• Graph iv

• Graph v

The figure summarizes the heights, in centimeters, of approximately  $400$  pine seedlings six years after they were planted at a center for environmental study. Approximately half of the trees were fertilized yearly, and the remaining trees were never fertilized. Which of the following statements about the medians and interquartile ranges (IQRs) of the heights of the two groups of trees six years after being planted is true ?

• The medians and the IQRs are the same for the unfertilized trees and the fertilized trees.

• The median for the unfertilized trees is greater than the median for the fertilized trees and the IQR is also greater for unfertilized trees. 

• The median for the unfertilized trees is the same as the median for the fertilized trees, and the IQR is greater for the unfertilized trees.

• The median for the unfertilized trees is less than the median for the fertilized trees, and the IQR is greater for the unfertilized trees.

• The median for the unfertilized trees is less than the median for the fertilized trees, and the IQR is less for the unfertilized trees.

Which of the following statistics is defined as the  $50^{th}$   percentile ?

• mean

• median

• mode

• interquartile range
  

• standard deviation
  

At a local ice-cream store,  $210$   people were surveyed on whether they preferred eating ice cream from a cone or a cup. Of the  $210$  people surveyed,  $70$  were adults and  $140$  were children. Of the responses,  $150$  indicated the cone as the preferred method of eating ice cream. For those surveyed, there was no association between age and preferred method of eating ice cream. Which of the tables shows the distribution of the responses ?

• Graph i
  

• Graph ii
  

• Graph iii
  

• Graph iv
  

• Graph v
  

Data are collected for the  $30$  students in an AP Statistics class.  Which of the following is NOT a variable for the data set ?

• student birth month
  

• political affiliation of student
  

• student age
  

• student address
  

• number of students in the data set
  

Which of the following variables for data about a track team is a discrete variable ?

• The height of a team member.

• The weight of a team member.

• The number of times a team member finished in first place in a race.

• The time recorded for the last race run by a team member.

• The length of distance leaped in the long jump by a team member.

The list shows the number of goals scored by a soccer team in each of  $9$  games.  How does the median number of goals scored compare with the mean number of goals scored ?

• The median is equal to the mean.
  

• The median is less than the mean by  $1$ .
  

• The median is greater than the mean by  $1$ .

• The median is less than the mean by   $2$ .
  

• The median is greater than the mean by   $2$ .