Exercise 11.3

1.

Use the regression module to obtain the Wilcoxon fit for the above data.

2.

The scores below are test scores for students in a Stat class over two tests, Test 1 and Test2.

            Test 1

                37    17    23    40    37    39    35    29    32    40    26    39    34 
                29    38    21    36    38    14    27    34    38    25    18    39    37 
                36    12    34    26 
             
            Test 2  (Paired data, first student scored 37, 28 on tests 1 and 2 respectively)

                28    24    20    32    39    36    40    33    23    36    21    30    30 
                21    22    24    27    20     8    31    28    30    25    16    31    18 
                25     6    36    20

(a)

Plot the data, Test 2 versus Test 1.

(b)

Use the summary module to find the standard deviations of the two data sets. Do you think these data will exhibit the regression towards the mean effect?

(c)

Use regression module to obtain the Wilcoxon fit. Do the data exhibit the regression towards the mean effect?