For margin of error to be a maximum of 3:
3 = z*(SD / sqrt(n)), where z is the z-score, SD is the standard deviation and n is the sample size.
z = 1.96 for a 95% confidence interval, and we are given SD = 15.
3 = 1.96*15/sqrt(n)
sqrt(n) = 9.8
n = 96.04 ~ 96 commercials.
The answer is 28 for the volume
Slope is the change in Y over the change in X:
Slope = (6 - -8) / (5 - -3)
Slope = (6+8) / (5+3)
Slope = 14/8
Slope = 7/4
Rotation
It’s rotating 90 degrees counterclockwise