Question

A random sample of size 15 taken from a normally distributed population revealed a sample mean of 75 and a sample variance of 25. The upper limit of a 95% confidence interval for the population mean would equal:

Answer 1

Answer:

77.53

Step-by-step explanation:

Sample size (n) = 15

Sample mean (μ) = 75

Sample variance (V) = 25

Sample standard deviation (σ) = 5

For a 95% confidence interval, z-score = 1.960

The upper limit of the confidence interval is defined as:

$UL=\mu+z\frac{\sigma}{\sqrt{n}}\\UL=75+1.960\frac{5}{\sqrt{15}} \\UL = 77.53$

Therefore, the upper limit of the 95% confidence interval proposed is 77.53.