Neas-Seminars

Fox Module 17: Unusual and influential data HW


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By NEAS - 12/3/2009 2:17:37 PM

Fox Module 17: Unusual and influential data

 

(The attached PDF file has better formatting.)

 

Homework assignment: hat values

 


           A statistician regresses the points Y = (5, 4, 3, 2, 1) on X = (1, 2, 3, 4, 15).

           The five points are (1,5), (2,4), (3, 3,), (4, 2), and (15,1).


 

 


 

A.     What is the mean hat value for these five points?

B.     What is the range of hat values for these five points?

C.    What are the hat values of the five points?

 

 
By 55Dollar5DollarFootLong - 8/11/2011 10:09:52 AM

I am kinda confused on the discussion regarding what the denominator should be when calculating the mean hat value. On the practice problem sheet, there is a row on the bottom of the data which gives averages, and the result for the average of the hat values uses the total number of observations as the denominator. However, from reading the posts above, the consensus seems to be to divide the total by 1.

Bubba Gump, you list your answer for part A as being k=1 with no mention of the mean hat value. Is all this discussion in regards to a previous version of HW #17 which had a different question for part A?