Homework 2 Solutions

4.30.  I can't reproduce the stem-and-leaf plot here.  So ask me or your TA if you need help with (a).
b) Your description should compare center, spread, and shape.  For example, the American  League tends to have a slightly higher number of runs; it looks like the mode, and possibly the median and mean, are all higher than the Nat'ls.  However, the National League's runs are much more spread out; the bulk are from  79 ot 116,  whereas for the American league all of the data lie between 83 and 111. Both distributions are fairly clustered, symmetric, and unimodal, although note the outlier in the National leage (which answers (c)).

5.21
a) In both you see the shape is mostly symmetric, with a slight skew to the right.  And in both you see the two outliers.  You also see that the bulk of the data lie between about 16 and 24 years, more or less.
b) The histogram reveals a large peak between 16 and 20 years, and a second peak around 22-24 years.
c) The outliers mean that you should use the median.
d) Again, the outliers mean that the IQR would be a better measure of spread than the standard deviation.