Boxplots, Scattergrams, Probability

A sample was taken of the salaries of 20 employees of a large company.  The box plot shows the salaries (in thousands of dollars) for this year.
Based on the boxplot, the five-number summary is...

• 28, 39, 48, 60.5, 77
• 28, 41, 48, 58, 77
• 28, 39, 51, 58, 77
• 28, 41, 51, 60.5, 77

What percent of the data is between 25 and 30 on the number line?

• 25%
• `50%
• 75%
• 100%

If you were in the 3rd quartile for the class.  Which is true?

• You are 75% taller than the rest of the class.
• You are 75 inches.
• You are taller than 75% of the class.
• You are shorter than 75% of the class. 

What is the overall shape of the graph?

• Approximately Symmetrical
• Skewed left
• Skewed right

What is the IQR of the Cruisers?

• 4
• 6
• 5
• 2

Using the information below, identify which of the following is NOT an outlier:
Q1 = 53
Q2 = 55
Q3=61

• 73
• 40
• 80
• 73.5

These box plots compare the number of triples (3-base hits) in Major League Baseball in 1979 and 2004, for all batters with at least 500 plate appearances.  Based on these box plots, which statement below is the only one that is not true?

• In 1979, a batter with 10 triples was not considered an outlier, but in 2004, 10 triples was an outlier 
• Since the median in 1979 was 4 and the median in 2004 was 2, there were twice as many triples hit in 1979 as there were in 2004
• About 75% of the batters in 1979 had at least 2 triples
• The IQR was higher in 1979 than in 2004  

If you do not like to wait, which restaurant would you prefer to go to and why?

• Lucy's Steakhouse because it has the shortest wait time.
• Gary's Grill because it has the an average wait time of 15 minutes.
• Gary's Gill because 75% of the time the wait time is under 20 minutes.
• Lucy's Steakhouse because 50% of the time the wait time is under 21 minutes.

Different writers have different styles.  One way to quantify this difference is to compare the distribution of word lengths in their work.  Above are parallel boxplots describing the distributions of word lengths for the first 60 words in Henry James’s The Turn of the Screw,  J.K. Rowling’s Harry Potter and the Chamber of Secrets, and Chapter 1 of your statistics textbook (labeled “Starnes” below). Based on the graphs, which one of the following statements must be true?

• Dot plots of the distributions of James’s word lengths and Starnes’s word lengths are identical.
• The longest word in the distribution of Rowling’s word lengths is shorter than 25% of the words in the “James” distribution.
• The range of Rowling’s word lengths is smaller than the interquartile range of Starnes’s word lengths.
• The median word length for Rowling is longer than for either Starnes or James.