A random sample of 64 observations produced a mean value of 82 and standard deviation of 5.5. The 90% confidence interval for the population mean $\mu$ is between
A) 81.86 and 82.14
B) 80.65 and 83.35
C) 80.87 and 83.13
D) 81.31 and 82.69
E) None of the above answers are correct.

Question

Quizplus · Accepted Answer

The 90% confidence interval is calculated using the formula: mean ± (Z * (standard deviation/√n)). For a 90% confidence level, Z is approximately 1.645. Thus, the interval is 82 ± (1.645 * (5.5/√64)), which results in 80.87 to 83.13.

A Random Sample of 64 Observations Produced a Mean Value μ\muμ

A Random Sample of 64 Observations Produced a Mean Value $\mu$