AP Statistics Comparing Displays

In a certain school, students can choose whether to eat in the school’s cafeteria. A reporter working for the school’s newspaper polled students on their reactions to changes in the menu at the cafeteria. For each student leaving the cafeteria in one 20-minute time period, the reporter used a die to determine whether to stop the student and ask how he or she felt about the new menu. In the reporter’s article it was stated that a random sample of the students showed that 23% of the school’s student population was happy with the new menu. Which of the following statements is true?

• Because each student leaving the cafeteria was randomly selected and could choose to answer or not, this is a random sample of the student population, and the 23% is an accurate measurement of the school population’s view of the new menu.

• Because students self-selected whether to eat in the cafeteria, the sampling method might be biased and the sample might not be representative of all students in the school.

• The survey would have been more effective if the reporter had collected the data in one 10-minute time period rather than in one 20-minute time period.

• The survey would have been more effective if students who cared about the food could have called the reporter to tell how they felt about the new menu, so that only students with opinions on the subject would have been surveyed.

• Because no treatment was imposed on the students eating in the cafeteria, one cannot make any conclusions about the new menu.

According to the 1.5 x IQR rule, how many outliers are there in the data set 72, 110, 114, 115, 118, 123, 144, 156?

• None

• One

• Two

• Three

A person travels by car.  They record their miles driven in a data table.  Calculate the linear regression equation of this data.

• y = 61.93x - 1.79

• y = -1.79x + 61.93

• y = 0.016x + 0.03

• y = 0.03x + 0.016

How many students scored 40% or below on the test?

• 21

• 22

• 20

• 15

What is the Interquartile Range?

• 28 cm

• 12 cm

• 33 cm

• 5 cm

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

The boxplots above summarize two data sets, A and B.

Which of the following must be true?

 

I. Set A contains more data than Set B.

II. The box of Set A contains more data than the box of Set B.

III. The data in Set A have a larger range than the data in Set B.

• I only

• III only

• I and II only

• II and III only

• I, II, and III

The back-to-back stem-and-leaf plot below gives the percentage of students who dropped out of school at each of the 49 high schools in a large metropolitan school district. Which of the following statements is NOT justified by these data?

• The drop-out rate decreased in each of the 49 schools between the 1989-90 and 1992-1993 school years.

• For the school years shown, most students in the 49 schools did not drop out of high school.

• In general drop-out rates decreased between the 1989-90 and 1992-1993 school years.

• The median drop-out rate of the 49 high schools decreased between the 1989-90 and 1992-1993 school years.

• The spread between the schools with the lowest drop-out rates and those with the highest drop-out rates did not change much between the 1989-90 and 1992-1993 school years.

How would you describe this graph? 

• Symmetric

• Skewed Right

• Skewed Left

• Bimodal