Use the sample information 11formula13.mml = 36, σ = 6, n = 11 to calculate the following confidence intervals for μ assuming the sample is from a normal population.
(a) 90 percent confidence. (Round your answers to 4 decimal places.) The 90% confidence interval is from to
(b) 95 percent confidence. (Round your answers to 4 decimal places.) The 95% confidence interval is from to
(c) 99 percent confidence. (Round your answers to 4 decimal places.) The 99% confidence interval is from to
(d) Describe how the intervals change as you increase the confidence level.