The following data give the prices of seven textbooks randomly selected from a university bookstore.
A. $91
B. $176
C. $108
D. $115
E. $56
F. $157
G. $144

a. Find the mean for these data. Calculate the deviations of the data values from the mean. Is the sum of these deviations zero?
Mean = $ Deviation from the mean for $176 = $ Sum of these deviations = $

b. Calculate the range, variance, and standard deviation. [Round your answers to 2 decimal places.] Range = $ Variance =

a) Mean = $121

Sum of deviations = $0

b) Standard deviation = 41.19

Variance = 1696.67

Range = $120

Step-by-step explanation:

We are given the following data:

$91 , $176 , $108 , $115 , $56 , $157 , $144

a) Mean and sum of deviations

Sum of deviations =

-30 + 55 - 13 - 6 - 65 + 36 + 23 = 0

The sum of deviations is zero dollars.

b) range, variance, and standard deviation

where are data points, is the mean and n is the number of observations.

Sum of square of differences =

900 + 3025 + 169 + 36 + 4225 + 1296 + 529 = 10180

Sorted data: 56, 91, 108, 115, 144, 157, 176

Range = Maximum - Minimum

Range = 176 - 56 = 120

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