Question

The president of a company that manufactures car seats has been concerned about the number and cost of machine breakdowns. the problem is that the machines are old and becoming quite unreliable. However, the cost of replacing them is quite high, and the president is not certain that the cost can be made up in today's slow economy. Top help make a decision about replacement, he gathered data about last month's costs for repairs and the ages (in months) of the plant's 20 welding machines. The data is below. Which of the following is INCORRECT?

A) slope = 2.47 means for each additional cost for repairs, the month of the plant's welding machines on average increases by 2.47

B) we have sufficient evidence to conclude that the age of a machine and its monthly cost of repair are linearly related

C) 56.6% of the variation in the cost of repair is explained by the age of a machine

D) the least squares line is Costs = 115 + 2.47 Age

Age	Repairs
110	327.67
113	376.68
114	392.52
134	443.14
93	342.62
141	476.16
115	324.74
115	338.98
115	433.45
142	526.37
96	362.42
139	448.76
89	335.27
93	350.94
91	291.81
109	467.8
138	474.48
83	354.15
100	420.11
137	416.04

Answer 1