Discuss the following:
Q1. Find the mean, median, and mode for the set of scores in the following frequency distribution table.
X f
10 2
9 3
8 5
7 6
6 3
5 1
Q2. A sample of N =5 scores has a mean of M = 12. If one person with a score of X = 8 is removed from the sample, what will be the value for the new mean?
Q3. A population of N = 8 scores has a mean of U =20. If one score is changed from X = 14 to X = 30, what will be the value for the new mean?
Q4. One sample of n =20 scores has a mean of M =50. A second sample of n = 5 scores has a mean of M= 10. If the two samples are combined, what is the mean for the combined sample?
Q5. Identify the circumstances in which the median rather than the mean is the preferred measure of central tendency.
Q6. One question on a student survey asks: In a typical week, how many times do you eat at a fast food restaurant? The follwoing frequency distribution table summarizes the results for a sample of n =20 studdents .
Number of times per week F
5 or more 2
4 2
3 3
2 6
1 4
0 3
a. Find the mode for this distribution
b. Find the median for the distribution
c. Explain why you cannot compute the mean number of times sing the data table.
Comparing measures of variability
Q7. Can SS ever have a value less than zero? Explain your answer
Q8. What does it mean for a sample to have a standard deviation of s = 5? Describe the scores in such of a sample (Describe where the scores are located relative to the sample mean).
Q9. A student was asked to compute the mean and standard deviation for The following sample of n = 5 scores: 81,87, 89, 86, and 87. To Simplify the arithmetic; the student firs subtracted 80 points from each Score to obtain a new sample consisting of 1, 7, 9, 6, and 7. The mean And standard deviation for the new sample were then calculated to be M = 6 and s = 3. What are the values of the mean and standard deviation? For the original sample?
Q10. For the folllowing sample of n = 7 scores
12, 1, 10, 6, 3, 3, 7
Compute SS, Variance and standard deviation for the sample. (How well Does your estimate compare with the actual value of s?)
Q11. Calculate SS, Variance and standard deviation for the following Sample of n =4 scores: 3, 1, 1, 1. (Note; the computational formula Works best with this scores)