AP STATS Warm Up #3

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

• stemplots are better at displaying very large sets of data

• stem plots never require rounding of values

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

The following is a histogram showing the distribution of the average property damage caused by tornadoes per year over the period 1950 to 1999 in each of the 50 states and Puerto Rico. The data are ​in millions of dollars and the class intervals are “0 to < 10,” “10 to < 20,” and so forth.

       The histogram…

• is skewed to the right

• shows a range in property damage of about 90 million dollars

•  has a center of about 10 million dollars

• All of these are true

A stemplot of ages of 18 faculty members in a college math department follows. 4|3 represents 43 ​years. If the eldest faculty member retires and is replaced by a 26-year-old, the median age will

• decrease by 2 years.

• stay the same.

•  increase by 2 years.

• increase by 4 years.

• None of the above statements is true.

 An airline recorded the number of on-time arrivals for a sample of 100 flights each day. The boxplot below summarizes the recorded data for one year. Based on the boxplot, which of the following statements must be true?

• The range of the number of on-time arrivals is greater than 90.

• The interquartile range of the number of on-time arrivals is 22.

• The number of days that had at least 80 on-time arrivals is greater than the number of days that had at most 76 on-time arrivals.

• The number of days that had from 76 to 80 on-time arrivals is equal to the number of days that had at most 76 on-time arrivals.

• The difference between the median and the lower quartile for the number of on-time arrivals is less than 2.

A company determines the mean and standard deviation of the number of sick days taken by its employees in one year. Which of the following is the best description of the standard deviation?

• Approximately the mean distance between the number of sick days taken by individual 

  employees and the mean number of sick days taken by all employees

• Approximately the median distance between the number of sick days taken by individual employees and the median number of sick days taken by all employees

• The distance between the greatest number of sick days taken by an employee and the mean number of sick days taken by all employees

• The number of days separating the fewest sick days taken and the most sick days taken when considering all employees

• The number of days separating the fewest sick days taken and the most sick days taken when considering the middle 50 percent of the distribution

Using the information below, identify which of the following is NOT an outlier:

Q1 = 53

Q2 (med) = 55

Q3=61

• 73
• 40
• 80
• 73.5