1.The test statistic used to test hypotheses about the population variance is given by Χ2 = (n - 1)s2 / σ2, which is chi-squared distributed with n - 1 degrees of freedom when the population is normally distributed with variance equal to σ2.
2.If we have some idea about the value of sample proportion p-hat , we use that value in determining thesample size needed to estimate the population proportion p.
3.In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion p-hat, we:
Select one:
a. take two more samples and average p-hat
b. let p-hat=0.5
c. take another sample and estimate p-hat
d. let p-hat=0.05 (the default α)