Question

An equation was used to predict possible sales of phones for 6 months. The actual sales of phones are also listed.

Actual sales
55 150 325 510 780 990


Predicted sales
40 150 300 500 800 1,000

The sum of the residuals is ______.

Answer 1

They were up 15+0+25+10-20-10=20. The sum was 20 :)

Answer 2

Answer with Step-by-step explanation:

Residual is calculated by the difference between actual value and the predicted value.

Actual sales Predicted sales Residual

55 40 15

150 150 0

325 300 25

510 500 10

780 800 -20

990 1000 -10

Sum of residuals=15+0+25+10-20-10

=20

Hence, sum of residuals is:

20