Assignment:
One sample has a mean of M=4 and a second sample has a mean of M=9. The two samples are combined into a single set of scores.
a. What is the mean for the combined set if the first sample has n=4 scores and the second sample has n=6?
b. What is the mean for the combined set if the first sample has n=6 scores and the second sample has n=4?
2. For the following population of N = 8 scores: 1, 6, 1, 1, 1
a. Calculate the range and the standard deviation. (Use either definition for the range)
b. Add 2 points to each score and compute the range and the standard deviation again. Describe how adding a constant to each score influences measures of variability.
3. After 2 points have been added to every score in a sample, the mean is found to be M=75 and the standard deviation is s=4. What were the values for the mean and standard deviation for the original sample?
b. After every score in a sample has been multiplied by 2, the mean is found to be M=40 and the standard deviation is s=6. What were the values for mean and standard deviation for the original sample?
4. Calculate the SS, variance, and standard deviation for the following sample of n=6 scores: 6, 4, 6, 5, 4, 5 (Note: The computational formula for SS works well with these scores.)
5. Calculate the SS, variance, and standard deviation for the following population of N=8 scores: 8, 7, 7, 9, 8, 7, 9, 9 (Note: The computational formula for SS works well with these scores.)