Which table should be used to determine a confidence interval on the mean when the standard deviation is not known?

OPTIONS

• F-Table
• T-Table
• Z-Table
• Chi-Square

ANSWER

T-Table

EXPLANATION

Chi-Square and F-tests are used for determining difference in variances between data sets. The Z-table is used for calculating Mean only whenever the standard deviation is known for the population. The t-test distribution is used when the population variance is unknown and the sample size is small (less than 30). That is why T-test is the right answer.