Sum of squares using computational formula
1. A student was asked to compute the mean and standard deviation for the following sample of n = 5
81, 87, 89, 86, & 87. To simplify the arithmetic, the student first subtracted 80 points from each score to obtain a new sample consisting of 1, 7, 9, 6, & 7. The mean and the standard deviation for the new sample were then calculated to be M = 6 and s = 3. What are the values of the mean M and standard deviation s for the original sample? Hint: What happens to the mean when you subtract a constant from each observation?
2. There are two different formulas or methods that can be used to compute SS.
1. Under what circumstance is the definitional formula easy to utilize? Hint: Refer to the text
2. Under what circumstance is the computational formula easy to utilize? Hint: Refer to the text