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Topic: [ap-stat] MC question
Replies: 1   Last Post: Apr 20, 2012 10:41 AM

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 Deborah L. Arnold Posts: 6 Registered: 11/4/11
[ap-stat] MC question
Posted: Apr 20, 2012 8:38 AM

An explanation of the following answer would be greatly appreciated.

Consider n pairs of numbers (x1, y1), (x2, y2), . . . , (xn, yn). The mean and standard deviation of the x-values are xbar = 5 and sx = 4, respectively. The mean and standard deviation of the y-values is ybar = 10 and sy = 10, respectively. Of the
following, which could be the LSRL?

A) y-hat = -5.0 + 3.0x
B) y-hat = 3.0x
C) y-hat = 5.0 + 2.5x
D) y-hat = 8.5 + 0.3x
E) y-hat = 10.0 + 0.4x

I can narrow it down to A or D since (xbar, ybar) has to be on the LSRL. D is stated to be the correct answer but I can't determine why.

Thanks for the help!

Deb Arnold
Math Teacher
Lakeville South High School

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