Stat 160 postquiz over sections 9.1 - 9.4


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1.     Consider the two data sets (from independent populations) given below. What are the estimates of Delta (triangle symbol) (location of Y population - location of X population) using the Wilcoxon, Median, and Mean, respectively.(Hint: Since this is a two sample test, you could do this by hand or use your Class Codes)
X:    8    13    111

Y:   18    12     14    12

0, 0, -30
6, 0, -30
0, 0, -28.33
7, 5.5, -28.33
2.     Consider two samples, X and Y, randomly taken from two independent populations. Determine the Wilcoxon estimate of Delta (the triangle symbol), the difference in location between the two populations.(Hint: Again, your Class Codes can check your answer if you do this problem by hand)
X:    12   16   18   25   30

Y:     8   10   19   22   28

0
10
-3
8.5
3.     Polls concerning the president's approval rating were taken in two states, A and B. Which of the following is an estimate of the difference in approval ratings between the two states?
           Approve      Disapprove
State A      25            38
State B      44            40

19
-19
-.020
.127
4.     The following are 100 estimates of Delta obtained via 100 resamples. What is a 95% confidence interval for Delta based on resampling?
-2.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0
-1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0    -1.0
-1.0    -1.0    -1.0    -1.0    0.0     0.0     0.0     0.0     0.0     0.0
0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0
0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0     0.0
0.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0
1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0
1.0     1.0     1.0     1.0     1.0     1.0     1.0     1.0     2.0     2.0
2.0     2.0     2.0     2.0     2.0     2.0     2.0     2.0     2.0     2.0
2.0     2.0     2.0     2.0     2.0     2.0     2.0     2.0     3.0     3.0

(95,100)
(-1.0, 2.0)
(-2.0, 3.0)
(-1.0, 1.0)
5.     Consider the following situation: