1) Student was enquired to find out mean and standard deviation for sample of n = 5 given below:

81, 87, 89, 86, and 87. To make simpler the arithmetic, student first subtracted 80 points from each score to get a new sample consisting of 1, 7, 9, 6, and 7. The mean and the standard deviation for new sample were then computed to be M = 6 and s = 3. Determine the values of the mean M and the standard deviation s for original sample?

2)  There are two various formulas or methods which can be utilized to compute SS.

Under what situation is the definitional formula easy to utilize?

Under what situation is the computational formula easy to utilize?

3) A sample of n = 9 has mean of M = 10. One person with score of X = 2 is separated from sample. Determine the value of the new sample mean?

4) Does it ever appear to you that weather is nice during work week, but dreadful on the weekend? Cerveny and Balling have confirmed that this is not your imagination; pollution accumulating during work week most probable spoils weekend weather for people on Atlantic coast. Suppose that the following hypothetical data the daily amount of rainfall for 10 wks in the summer given below.

Rainfall on Weekdays              1.2, 0.6, 0.0, 1.6, 0.8, 2.1, 0.2, 0 .9, 1.1, 1.4
Rainfall on Weekends              1.5, 2.0, 1.8, 1.5, 2.2  2.4, 0.8,  1.6, 1.2, 1.7

a) Compute average daily rainfall in the week and for weekends.

b) Based on two means, does there show e a pattern in data? Based on the part (a) formulate the conclusion.