Supplementary Exercises 1.51 and 1.77 of IPS7e 
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Minitab commands and output:

 WOpen "R:\Chapter 1\ex01_051.mtw".

 Histogram 'days';
   Bar.

 Dotplot 'days'.

 Stem-and-Leaf 'days'.

Stem-and-Leaf Display: days 

Stem-and-leaf of days  N  = 72
Leaf Unit = 10

 2    0  44
 30   0  5555566777888888888889999999
(24)  1  000000000001112222333444
 18   1  56777899
 10   2  1144
 6    2
 6    3  2
 5    3  8
 4    4  0
 3    4
 3    5  12
 1    5  9


Answers to questions in 1.51:
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The distribution (shape) is clearly right-skewed. The center is roughly
about 100. The spread is considerable (range 43-598). There are no obvious 
outliers because no single observation seems to be clearly different from
the others, and nor do any group of observations seem clearly different
from the others. Notice that the right-skewedness of the distribution
means that some scattered large observations could be perfectly acceptable.


Additional questions in 1.77:
------------------------------
 Describe 'days'.

Descriptive Statistics: days 

Variable   N  N*   Mean  SE Mean  StDev  Minimum    Q1  Median     Q3  Maximum
days      72   0  141.8     12.9  109.2     43.0  82.3   102.5  153.8    598.0

 Boxplot 'days';
   IQRBox;
   Outlier.


Comments:
---------
The data are skewed to the right, so the five-number summary is more
adequate to describe the data than the mean and the standard deviation;
notice the big difference between mean and median! 

Half the guinea pigs lived less than 102.5 days; typical lifetimes were
82 to 154 days. The longest-lived guinea pig died just short of 600
days, while one guinea pig lived only 43 days.

The boxplot indicates 6 points by asterisks, as suspected outliers.
This is however due to the right-skewness of the distribution, and the
plots give no reason to suspect that any of these observations are
substantially different than the others (except that they are the
largest ones, of course!).