宇同学2023-01-01 21:07:43

Find the reliability factors based on the t-distribution for the following confidence intervals for the population mean (df = degrees of freedom, n = sample size): A.A 99% confidence interval, df = 20 A 90% confidence interval, df = 20 C. A 95% confidence interval, n = 25 D. A 95% confidence interval, n = 16 A. For a 99% confidence interval, the reliability factor we use is t0.005; for df = 20, this factor is 2.845. B. For a 90% confidence interval, the reliability factor we use is t0.05; for df = 20, this factor is 1.725. C. Degrees of freedom equals n − 1, or in this case 25 − 1 = 24. For a 95% confidence interval, the reliability factor we use is t0.025; for df = 24, this factor is 2.064. D. Degrees of freedom equals 16 − 1 = 15. For a 95% confidence interval, the reliability factor we use is t0.025; for df = 15, this factor is 2.13 课后答案中的t0.005 t0.05 t.0.025 t0.025这几个数是怎么来的？