Question

Given the sample results taken from a normal population distribution: mean = 4.65, σ = 0.32, and n = 13. Find the margin-of-error and the 95% confidence interval for the population mean. (use 2 decimal places)

Answer 1

Solution :

Given that,

Population standard deviation =    = 0.32

Sample size n =13

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96   ( Using z table )

Margin of error = E =   Z/2    * ( /n)
=1.96 * (0.32 / 13)

E= 0.17