Since F(X) = 3^X,
F(4) = 3^4 = 81
To find the mean (average), we first need to add up all the test scores (14 + 19 + 19 + 20 + 16 + 18 + 15 + 17 + 12 = 150). Then, we need to divide that number (150) by the number of numbers in the data set (9 in this case). So the mean of these test scores is about 16.6666666667.
At 0 hours: 24 boxes
After 1 hour: 24/2 = 12 boxes
After 2 hours: 12/2 = 6 boxes
After 3 hours: 6/2 = 3 boxes
She will have 3 boxes after 3 hours.
Hope this helps :)