Chapter 5.5, Problem 73E

73. Employee training. A company producing computer components has established that, on the average, a new employee can assemble N(t) components per day after t days of on-the-job training, as indicated in the following table (a new employee’s productivity usually increases with time on the job, up to a leveling-off point):

t	0	20	40	60	80	100	120
N(t)	10	51	68	76	81	84	85

1. (A) Find a quadratic regression equation for the data, and graph it and the data set in the same viewing window.
2. (B) Use the regression equation and a numerical integration routine on a graphing calculator to approximate the number of units assembled by a new employee during the first 100 days on the job.