________ is the process of systematically selecting representative elements of a population

In order to estimate the average time spent on the computer terminals per student at a local university, data were collected from a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.2 hours. With a .95 probability, the margin of error is approximately_____

a. .26 b. 1.96 c. .21 d. 1.64

The length of the estimated duration of an activity

a. should last as long as the project. b. is divided by the number of resources assigned to the task. c. is dependent upon the time required for the predecessor activity. d. should not be longer than the review of the actual project progress.