2.32 
a.  mean=2761;median=2450
b. the median should be preferred b/c there is a large 
observation (4700, called outlier in statistical jargon)
which will inflate the center.
i.e. median is more "robust" than mean.

2.48
mean=91

2.66 
a. variance=1.7 (=[(-1.2)^2+(-1.2)^2+(-.2)^2+(,8)^2+(1.8)^2]/(5-1))
b. stdev=1.3

2.72
a. stdev is the measure of variation; variance=7.61^2=57.91
b.IQR=14-5=9; IQR measures the length between 25percentile and 75percentile.
c. any number larger than 7.61