Question

The Quality Control Department employs five technicians during the day shift Listed below is the number of times each technician instructed the production foreman to shut down the manufacturing process last week.
Technician Shutdown
Taylor 4
Hurley 3
Gupta 5
Rousche 6
Huang 3

Required:
a. How many samples, without replacement, of size two are possible?
b. Compute the mean of the sample means and compare it to the population mean. (Round your answers to 1 decimal place.)

Answer 1

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  $=\frac{42}{10}$    = 4.2

Mean of population is = $\frac{4+3+5+6+3}{5}$    = 4.2

Thus both the means are equal.