Solution :
Number of different samples of two technicians possible is = 10, as 2 technicians are to be chosen from a total of 5 technicians.
a). Therefore, 10 different samples are possible of size two.
b).
Sample Shut down Mean
1. Taylor, Hurley 4, 3 3.5
2. Taylor, Gupta 4, 5 4.5
3. Taylor, Rousche 4,6 5
4. Taylor, Huang 4, 3 3.5
5. Hurley, Gupta 3,5 4
6. Hurley, Rousche 3,6 4.5
7. Hurley, Huang 3,3 3
8. Gupta, Rousche 5,6 5.5
9. Gupta, Huang 5,3 4
10. Rousche, Huang 6,3 4.5
42
Now mean of sample means
= 4.2
Mean of population is =
= 4.2
Thus both the means are equal.