Answer:
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
![\sigma = \sqrt{\dfrac{10180}{6}} = 41.19\\\\\sigma^2 = 1696.67](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%5Csqrt%7B%5Cdfrac%7B10180%7D%7B6%7D%7D%20%3D%2041.19%5C%5C%5C%5C%5Csigma%5E2%20%3D%201696.67)
Sorted data: 56, 91, 108, 115, 144, 157, 176
Range = Maximum - Minimum
Range = 176 - 56 = 120