The sampling distribution used to make inferences about a single population variance is:
a. a normal distribution
b. a t distribution
c. an F distribution
d. a chi-square distribution
e. none of these
Q. 2Random variation in a process can be eliminated.
Indicate whether the statement is true or false
Q. 3A random sample of 20 observations is selected from a normally distributed population. The sample variance is 12 . In the 95 confidence interval for the population variance, the upper limit will be:
a. 6.940
b. 7.564
c. 22.536
d. 25.599
e. 27.392
Q. 4If a process is in control, we expect all the data values to fall within three standard deviations of the mean.
Indicate whether the statement is true or false
Q. 5The shape of the chi-squared distribution depends on:
a. the population variance
b. the number of its degrees of freedom
c. the population mean
d. all of these
e. none of these
Q. 6If a process is in control, we expect all the data values to fall within two standard deviations of the mean.
Indicate whether the statement is true or false
Q. 7The chi-squared distribution is:
a. symmetric around zero
b. positively skewed
c. negatively skewed
d. mound-shaped
e. positively skewed and mound-shaped
Q. 8If a process is in control, we expect all the data values to fall within one standard deviation of the mean.
Indicate whether the statement is true or false
Q. 9A right-tailed area in the chi-squared distribution equals 0.05 . For 8 degrees of freedom the critical value equals 13.362.
Indicate whether the statement is true or false
Quick Reply
