ANSWER THE FOLLOWING

6. The variance of a sample of 81 observations equals 64. The standard deviation of the sample equals

a. 0 B. 4096 c. 8 d. 6561

_____7. Which of the following is not a measure of dispersion

a. range

b. 50th percentile

c. standard deviation

d. variance

_____8. If the variance of a data set is correctly computed with the formula using n - 1 in the denominator, which

of the following is true?

a. the data set is a sample

b. the data set is a population

c. the data set could be either a sample or a population

d. the data is from a census

_____9. The measure of dispersion that is influenced most by extreme values is

a. variance

b. standard deviation

c. range

d. interquartile range

_____10. The descriptive measure of dispersion that is based on the concept of a deviation about the mean is

a. range

b. interquartile range

c. both and b

d. standard deviation

B. Solve the following and show your complete solution.

1. Calculate the standard deviation of the set of first 5 natural numbers when n is an odd number.

2. Calculate the standard deviation of the set of first 6 natural numbers when n is an odd number.

3. The data on relative humidity (in %) for the first ten days of the month in a city are given below:

90 97 92 95 93 95 85 83 85 75

Calculate the range, variance, and standard deviation.