Modern Business Statistics with Microsoft Excel 5th Edition By David R. Anderson – Test Bank

CHAPTER 11—INFERENCES ABOUT POPULATION VARIANCES

MULTIPLE CHOICE

1. A sample of 28 elements is selected to estimate a 95% confidence interval for the variance of the population. The chi-square values to be used for this interval estimation are
a. -1.96 and 1.96
b. 14.573 and 43.195
c. 16.151 and 40.113
d. 15.308 and 44.461

ANS: B PTS: 1

2. We are interested in testing whether the variance of a population is significantly less than 1.44. The null hypothesis for this test is
a. Ho: 2  1.44
b. Ho: s2  1.44
c. Ho:  1.20
d. Ho: 2  1.44

ANS: D PTS: 1

3. A sample of 41 observations yielded a sample standard deviation of 5. If we want to test Ho: 2 = 20, the test statistic is
a. 100
b. 10
c. 51.25
d. 50

ANS: D PTS: 1

4. The value of F.05 with 8 numerator and 19 denominator degrees of freedom is
a. 2.48
b. 2.58
c. 3.63
d. 2.96

ANS: A PTS: 1

5. To avoid the problem of not having access to Tables of F distribution with values given for the lower tail, the numerator of the test statistic should be the one with
a. the larger sample size
b. the smaller sample size
c. the larger sample variance
d. the smaller sample variance

ANS: C PTS: 1

6. The symbol used for the variance of the population is
a.
b. 2
c. s
d. s2

ANS: B PTS: 1

7. The symbol used for the variance of the sample is
a.
b. 2
c. s
d. s2

ANS: D PTS: 1

8. The random variable for a chi-square distribution may assume
a. any value between -1 to 1
b. any value between – infinity to +infinity
c. any negative value
d. any value greater than zero

ANS: D PTS: 1

9. A sample of n observations is taken from a population. When performing statistical inference about a population variance, the appropriate chi-square distribution has
a. n degrees of freedom
b. n – 1 degrees of freedom
c. n – 2 degrees of freedom
d. n – 3 degrees of freedom

ANS: B PTS: 1

10. For an F distribution, the number of degrees of freedom for the numerator
a. must be larger than the number of degrees for the denominator
b. must be smaller than the number of degrees of freedom for the denominator
c. must be equal to the number of degrees of freedom for the denominator
d. can be larger, smaller, or equal to the number of degrees of freedom for the denominator

ANS: D PTS: 1