问题如下:
For a sample size of 65 with a mean of 31 taken from a normally distributed population with a variance of 529, a 99% confidence interval for the population mean will have a lower limit closest to:
选项:
A. 23.64.
B. 25.41.
C. 30.09.
解释:
A is correct.
To solve, use the structure of Confidence interval = Point estimate ± Reliability factor × Standard error, which, for a normally distributed population with known variance, is represented by the following formula:
For a 99% confidence interval, use z0.005 = 2.58. Also, σ = = 23. Therefore, the lower limit = .
老师好!我想请问一下,这种计算一般按计算器有没有什么便捷的方法?因为我目前都是一步一步地计算,不知道怎么样可以一步算出整个式子。谢谢!