Linear Equations · Exercise 3
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:
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 \overset{^}{y} = -2.5 x + 60. We compute the average price per widget if 30 are purchased and observe which of the following?
(a) \overset{^}{y} = 15 \text{dollars}; obviously, we are mistaken; the prediction \overset{^}{y} is actually +15 dollars.
(b) \overset{^}{y} = 15 \text{dollars}, which seems reasonable judging by the data.
(c) \overset{^}{y} = -15 \text{dollars}, which is obvious nonsense. The regression line must be incorrect.
(d) \overset{^}{y} = -15 \text{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.
OpenStax, Introductory Business Statistics 2e · §13.3 Linear Equations · Exercise 3
No hints for this one.
Check your full solution
Attach photos of your pages (up to 3) or one PDF — or check what you typed above. Lemma reads the work and verifies the reasoning, not just the answer.
Your first check today doesn't need an account.
Your photos and PDFs are read once and not stored — only the transcription is kept.