The standard error of the regression:
a. is based on squared deviations from the regression line.
b. may assume negative values if b1 < 0.
c. is in squared units of the dependent variable.
d. may be cut in half to get an approximate 95 percent prediction

the answer is

A. Is based on squared deviations from the regression line.

Step-by-step explanation:

since the numerator of standard error if N, squaring the value cannot give negative value. dependent variable are the squared units

0.85 or 85%

step-by-step explanation:

1) divide 23 by 27

2) round the decimal to the nearest 10

3) so your answer would be 0.85 or 85%