The following data give the prices of seven textbooks randomly selected from a university bookstore.

$89

$170

$104

$113

$56

$161

$147

a) Find the mean for these data (input the numerical value without the dollar sign). Calculate the deviations of the data values from the mean.

b) Is the sum of these deviations zero (yes or no)?

c) Calculate the range (do not include unit).

d) Calculate the variance.

e) Calculate the standard deviation (round to one decimal place).