#### 16. Sampling Distribution of the Sample Mean

*Question 1*

The 10 sample means for the cold water dissolving times of each set of 10 tablets in a row are

*Mean*

26.20

26.41

26.06

26.32

25.20

27.42

26.66

27.50

26.33

26.21

These 10 means have a standard deviation of 0.6626 seconds. The expected standard deviation is 2.49/√10 = 0.7874 seconds. From just 10 data sets the agreement is quite good.

The 10 sample means for the hot water dissolving times of each set of 10 tablets in a row are

*Mean*

18.49

19.20

15.88

16.49

16.79

16.98

16.27

16.67

15.84

16.64

These 10 means have a standard deviation of 1.0893 seconds. The expected standard deviation is 2.24/√10 = 0.7084 seconds. Again, from just 10 data sets the agreement is quite good.