All eight companies in the aerospace industry were surveyed as to their return on investment last year. The results are (in percent) 10.6, 12.6, 14.8, 18.2, 12.0, 14.8, 12.2, and 15.6. A. Calculate the variance.
B. Calculate the range.
C. Calculate the arithmetic mean.

Step-by-step explanation:

Given:

10.6, 12.6, 14.8, 18.2, 12.0, 14.8, 12.2, and 15.6

Number of companies (n) = 8

Required

A. Calculate the variance.

B. Calculate the range.

C. Calculate the arithmetic mean.

Calculating the variance. ...

We start by calculating the mean of the given data

Subtract the mean from each data

Square these results

Add these results

Divide result by n

Calculating the range. ..

Range is calculated as thus

From the given data;

So,

Calculating the arithmetic mean....

cosine

step-by-step explanation: