Question

PLEASE SHOW EXCEL FORMULA

1. normal population has parameters μ = 40 and σ = 8.
   1. What is the standard error of the sample mean for a sample size n = 64?
   2. Construct a ninety percent the confidence interval of the sample mean for a sample size n = 1,000.

Answer 1

normal population has parameters μ = 40 and σ = 8.

1. What is the standard error of the sample mean for a sample size n = 64?

Sample mean = μ = 40

standard error = σ / sqrt(n) = 8/sqrt(64) = 8/8 = 1

Construct a ninety percent the confidence interval of the sample mean for a sample size n = 1,000.

Obtain critical value using =NORM.S.INV(0.05) ( as it is two tailed )

z_c = 1.645

The corresponding confidence interval is computed as shown below:

CI = (39.584, 40.416)