Part A:
is the equation of the line.
Part B: Anika worked 17.5 hours on day 0.
Part C: The setup time decreases with 1 hour and 15 min per day.
Explanation:
Part A: Let us find the equation of the line using the points (2,15) and (6,10)
The equation of the line is given by,

Substituting, we get,

Simplifying, we have,


Subtracting both sides by 15, we get,

Hence, the equation of the line is 
Part B: To determine the number of hours Anika worked on day 0, let us substitute x = 0 in the equation of the line.
Thus, we get,

Hence, Anika worked 17.5 hours on day 0.
Part C: The setup time decrease per day can be determined using the slope.
The formula for slope is given by

Substituting , we have,

Converting the fraction into hours and minutes, we get,

Since, 1 hour = 60 min
Subtracting 60 and 75 = 15 min
Thus, the setup time decreases with 1 hour and 15 min per day.