A random sample of n = 16 observations from a normally distributed population with unknown mean μ and known standard deviation σ = 12 produced a sample mean X-bar = 15. Find a 95% confidence interval for the population mean μ.
15 ± 5.88
15 ± 0.42435
15 ± 1.47
15 ± 1.69741
The following random sample was selected from a normal distribution with unknown mean μ: 1, 3, 7, 8, and 11. Construct a 98% confidence interval for the population mean μ.
6 ± 4.161
6 ± 1.861
6 ± 2.998
6 ± 6.703