Answer:
The correct option is B.
Step-by-step explanation:
It is given that there is a strong, negative, linear relationship between x and y. where, x is the number of consecutive hours a worker has been assembling chainsaws and y is the number of chainsaws he can produce in an hour.
He finds that 70%of the variation in chainsaws produced per hour can be explained by the regression of y on x.


The slope is -0.7, therefore option B is correct.
Answer:
Lara's average speed :
average speed = total distance / total time
=> 8 miles / 2.5 hours
=> 3.2 mph
Tim's average speed :
= total distance / total time
= 12 miles / 3.5 hours
= 3.43 mph
therefore,
Tim's average speed (3.43 mph) is greater.