We are interested in finding the linear relation between the number of widgets purchased at one time and the cost per widget. The following data has been obtained:

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X: Number of widgets purchased - 1, 3, 6, 10, 15 Y: Cost per widget(in dollars) - 55, 52, 46, 32, 25 Suppose the regression line is y = -2.5x + 60. We compute the average price per widget if 30 are purchased and observe which of the following? ^ a. y = 15 dollars; obviously, we are mistaken; the prediction y is actually +15 dollars. ^ y = 15 dollars, which seems reasonable judging by the data. y = -15 dollars, which is obvious nonsense. The regression line must be incorrect. b. C. ^ d. y=-15 dollars, which is obvious nonsense. This reminds us that predicting Y outside the range of X values in our data is a very poor practice.