You intend to estimate a population mean with a confidence interval. You believe the population to have a normal distribution.

Question

You intend to estimate a population mean with a confidence interval. You believe the population to have a normal distribution. Your sample size is 73.

While it is an uncommon confidence level, find the critical value that corresponds to a confidence level of 91.3%.

(Report answer accurate to three decimal places with appropriate rounding.)

Answer 1

For a confidence level of 91.3, the level of significance will be 0.087. The tails will contain 0.0435 probability.

With a sample size of 73, the degrees of freedom are 72. The critical value can be looked up from the t-distribution table for a 0.0435 tail probability and DOF = 72