Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 58

Expand Your Knowledge: Split Stem The Boston Marathon is the oldest and best-known U.S. marathon. It covers a route from Hopkinton, Massachusetts, to downtown Boston. The distance is approximately 26 miles. Visit the Brase/Brase statistics site at www.cengagebrain.com and find the link to the Boston Marathon. Search the marathon site to find a wealth of information about the history of the race. In particular, the site gives the winning times for the Boston Marathon. They are all over 2 hours. The following data are the minutes over 2 hours for the winning male runners:

(a) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the years 1961 to 1980. Use two lines per stem.
PROCEDURE
HOW TO SPLIT A STEM
When a stem has many leaves, it is useful to split the stem into two lines or more For two lines per stem, place leaves 0 to 4 on the first line and leaves 5 to 9 on the next line.
(b) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the years 1981 to 2000. Use two lines per stem.
(c) Interpretation Compare the two distributions. How many times under 15 minutes are in each distribution