A computer engineer is investigating whether the amount of installed RAM (random access memory) can be used to predict the mean cost of a laptop with the operating system. The computer engineer collected a sample of 20 laptops with the same operating system. The engineer wants to estimate the mean change in the cost, in dollars, for each increase of 1 gigabyte of installed RAM. Assuming the conditions for inference have been met, which of the following inference procedures is the most appropriate for such an investigation? a. A two-sample z-interval for a difference between proportions.
b. A two-sample t-interval for a difference between means.
c. A matched-pairs t-interval for a mean difference.
d. A one-sample t-test for means.
e. A linear regression t-interval for slope