STA 6166 Homework #1 Spring 2005 Use the data in the “baseball” text file to work the following problems. The file contains SAS code which will construct two SAS data sets if you submit the code as a SAS program. You can use the entire program and work the problems using SAS, or you can extract the data and use another program. The first set of data contains earned run averages (ERA) for all National League pitchers in the year 2002. The second contains team batting averages for both the National and American Leagues. 1. Construct a frequency histogram of the National League ERA data. Do the data appear “mound-shaped?” Are the data skewed? Explain your answers. 2. Compute the mean, mode, and median of the NL ERA data. How do the three measures of central tendency rank? Explain the ranking. Why to think the mean is less than or greater than the median?3. Compute the range, inter-quartile range, and standard deviation of the NL ERA data. Does the Empirical Rule apply for these data? Explain. 4. Suppose you are trying to make inference about NL ERA values in general, not of this particular year. What would you identify as the “population?”5. Construct side-by-side box plots of the AL and NL team batting average data. What do you conclude about comparing the two leagues? Do the leagues seem to differ in mean batting average? Do they seem to differ in
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