A researcher wants to know whether the typing speed of secretary (in words per minute) is related to time (in hours) that it takes the secretary to learn to employ a new word processing program. The data are shown.
Determine the 90% prediction interval for time when the speed is 72 words per minute
Speed x: 48 74 52 79 83 56 85 63 88 74 90 92
Time y: 7 4 8 3.5 2 6 2.3 5 2.1 4.5 1.9 1.5