Which of the following statements is true? Question 6 options: Confidence intervals with higher confidence levels are always narrower than lower confidence levels. The critical value of a confidence interval for a population mean is a normal distributed Z value. A confidence interval comparing independent proportions is (0.146, 0.332), if we switch the point estimate from (sample proportion 1 - sample proportion 2) to (sample proportion 2 - sample proportion 1), the CI becomes (0.332, 0.146). The critical value of a confidence interval for a population mean is a t-distributed value