Question
Suppose there is a perfect negative correlation between the amounts of time spent (on average) answering each question on a test and the total score on the test. Assume that Mx=30 seconds, and sx=10 seconds for the time per item, and that My=70, with Sy=14 for the total score.
a. If someone spent 10 seconds per item, what total score would they receive?
b. If someone’s score on the exam was 49, how many seconds did they spend per item?
Question
A carpenter is building a rectangular room with a fixed perimeter of 324 ft. What dimensions would yield the maximum area? What is the maximum area?
Ben’s Bicycle Designs has determined that when x hundred bikes are built, the average cost per bike is given by C(x)=0.5x^2 – 1.6x+5.597, where C(x) is in hundreds of dollars. How many bikes should the shop build to minimize the average cost per bike?