AP STAT MCQ 1A

A group of middle school students were asked which school subject was their favorite. The results are displayed by grade of student in the following bar chart. ** Which of the following statements is supported by the bar chart?

A. For students who chose art, the number of grade 8 students was at least 100% greater than the number of grade 7 students. The grade 7 bar extends to at most 8 students. A 100% increase would reach 16 students, and the grade 8 bar extends to at least 16 students.

The following dotplot shows the number of strokes taken by 20 professional golfers competing at an 18-hole golf course.

A. Quantitative and discrete The number of strokes is a whole number.

The diameter, in centimeters (cm), of each tree in a random sample of trees in a forest was measured. The histogram shown summarizes the diameters. ** Which of the following is the best description of the distribution?

A. The distribution consists of two clusters and a gap. The best description indicates the noticeable gap between 25cmand 40cm. A cluster is a concentration of data. Based on the histogram, there appears to be two clusters of data.

Relative humidity is a measure, expressed as a percentage, of the amount of water vapor present in air. The following histogram summarizes the relative humidity, at noon, for a random sample of 100 days for a certain city. ** Based on the histogram, which of the following is the best description of the distribution?

A. The distribution displays a gap with a potential outlier located between 40% and 45%. There are no observed data values between 45% relative humidity and 55% relative humidity, so there is a gap displayed in the distribution. The value located between 40% and 45% is unusually small when compared with the other data values. The value is a potential outlier; to test that it is an outlier would require using the 1.5×IQR rule or using the two standard deviations rule.

Just before graduation, a random sample of high school seniors were asked what their plans were for the coming year. A year after graduation, those same individuals were asked what their main activity was in the year since graduation. Their responses are shown in the following bar chart. ** Which of the following statements is supported by the bar chart?

A. The percentage of students who selected Work as their main activity increased after graduation. The bars for Work increased from below 0.3 to above 0.3.

The occupancy rate of a motel is the percentage of rooms that are occupied on a particular night. The histogram shown summarizes the occupancy rates for a random sample of 100 nights for a motel. Based on the histogram, which of the following best describes the shape of the distribution of occupancy rates?

B. Skewed to the right The distribution of occupancy rates is skewed to the right because the right tail is longer than the left tail.

The following bar chart shows the number of wins for four middle-school basketball teams. Each team played 12 games. ** Which of the following statements is not supported by the bar chart?

B. Team B won 60% of its games. The statement is not supported by the bar chart. Team B won 6 games, and 6 out of 12 is 50%, not 60%.

A group of first-grade students were asked to name their favorite color. The responses are shown in the following frequency table. ** Which of the following statements is supported by the frequency table?

B. Twice as many students chose blue as chose red. The number of students who chose red is 15, and 30 students chose blue. Since 30 is twice 15, the statement "Twice as many students chose blue as chose red" is supported by the data in the table.

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

C. The number of times that a team member finished first in a race The number of times that a team member finished first in a race is a count and is a discrete number.

The following table shows data collected about the thirty-third through fortieth presidents of the United States. All variables reported in the table are categorical. ** Which of the variables in the table could have been reported differently such that the variable would be classified as quantitative?

D. Age at Inauguration Age at inauguration could have been measured as a number of years.

The following relative frequency table shows reasons given by high school students for their last absence from school. ** Which of the following statements is not supported by the relative frequency table?

D. Only 7 students were absent because they did not finish an assignment. The statement is not supported by the relative frequency table. The proportion of students who gave a reason of did not finish assignment is 0.07, meaning that 7% of the total number of students, T, gave this reason. The number of students giving this reason is 0.07T, but this number cannot be determined because T is not known.

The following bar chart shows the average price per gallon of gasoline for each month in 2004. ** Which of the following statements is not supported by the bar chart?

D. The gas price was lowest in February. The statement is not supported by the bar chart. January has the lowest bar in the bar chart, not February.

Residents from five districts of a city were asked whether they were in favor of a city proposal to create new bike lanes in the roads. The following bar chart shows the relative frequency in each district of those who responded that they were in favor of the proposal. ** Which of the following statements is supported by the bar chart?

E. District 2 has the greatest percentage of residents who are in favor of the proposal. The bars represent percentages, and District 2 has the highest bar (around 71%).

Students in a class were asked to choose their favorite school subject. The following frequency table summarizes the responses. ** Which of the following statements is supported by the frequency table?

E. Less than half of the students chose math as their favorite subject. Thirty-five percent of the students chose math as their favorite subject.

Data are collected on the 35 students in a college history course. Which of the following is not a variable for the data set?

E. Number of students in the data set A variable is a characteristic that can vary from student to student. The number of students in the data set is a single, fixed value (35).

The following table shows the numbers of students in grades 7 and 8 at a middle school who are participating in extracurricular activities. ** Which of the following statements is supported by the table?

E. The activity with the greatest number of students is Chorus. The total number of students in Chorus is 42, which is greater than the other totals.

The traffic engineer for a large city is conducting a study on traffic flow at a certain intersection near the city administration building. The engineer will collect data on different variables related to the intersection each day for ten days. Of the following variables, which will be measured using continuous data?

E. The number of minutes for a car to get from the intersection to the administration building The number of minutes is a continuous variable. Between any two minutes, fractions of a minute can always be recorded.

A local ice-cream shop sells ice-cream cones for $2.00, and customers can choose from the following options. Ice-cream flavor Type of cone: sugar or waffle Chocolate dipped for an additional $0.50 Sprinkles for an additional $0.50 Which of the following is a quantitative variable?

E. The total cost of the cone A quantitative variable is one that takes on numerical values for a measured or counted quantity. The total cost of the cone is a quantitative variable since it can assume different numerical values representing the cost of each cone. The total cost of a cone could be $2.00 (ice cream in cone only), $2.50 (ice cream with sprinkles only or ice-cream cone with chocolate only), or $3.00 (ice-cream cone that is both chocolate dipped and has sprinkles).