Given a regression cost function, y = 10 + 2x with a standard error of $3.40, and x represents the activity of direct labor hours, what is the estimated cost when x = 15?

a.$7.80c.$40.00

b.$15.60d.$80.00

Refer to the preceding question. What is the 95% prediction interval, using the non-precise guidelines discussed in the notes, for the true cost when the number of direct labor hours is 15?

a.$46.80 < the true cost < $33.20

b.$33.20 < the true cost <$46.80

c.$23.60 < the true cost < $46.80

d.Cannot be determined from the given information.