Multiple choice statistic questions: Chebyshev's Theorem, Standard Deviation, Coefficient of Variation, Relative Dispersion, Pearson's Coefficient, and Variance.

Please choose the BEST answer for the following questions:

1. According to Chebyshev's Theorem, what percent of the observations
lie within plus and minus 1.75 standard deviations of the mean?

A) 56%

B) 95%

C) 67%

D) Cannot compute because it depends on the shape of the distribution

E) None of the above

2. If the sample variance for a frequency distribution consisting of
hourly wages was computed to be 10, what is the sample standard
deviation?

A) $1.96

B) $4.67

C) $3.16

D) $10.00

E) None of the above

3. The coefficient of variation for a set of annual incomes is 18%; the
coefficient of variation for the length of service with the company is
29%. What does this indicate?

A) More dispersion in the distribution of the incomes compared
with the         dispersion of their length of service

B) More dispersion in the lengths of service compared with income

C) Dispersion in the two distributions (income and
service) cannot be compared using percents

D) Dispersions are equal

E) None of the above

4. Mr. and Mrs. Jones live in a neighborhood where the mean family
income is $45,000 with a standard deviation of $9,000. Mr. and Mrs.
Smith live in a neighborhood where the mean is $100,000 and the standard
deviation is $30,000. What are the relative dispersion of the family
incomes in the two neighborhoods?

A) Jones 40%, Smith 20%

B) Jones 20%, Smith 30%

C) Jones 30%, Smith 20%

D) Jones 50%, Smith 33%

E) None of the above

5. If the mean of a frequency distribution is smaller than the median
and mode, what is the sign of Pearson's coefficient of skewness?

_______________

6. The Pearson's coefficient of skewness is a measure of the lack of
symmetry of a distribution.

A) True

B) False

7. The ages of a sample of the typewriters used by the typists in the
typing pool were organized into the following table:

 

Ages (in years) Number

2 up to 5 2

5 up to 8 5

8 up to 11 10

11 up to 14 4

14 up to 17 2





What is the sample variance?

 

A) About 10.2

B) About 6.1

C) About 14.0

D) About 3.2

E) None of the above

8. The coefficient of variation is a measure of _______________.