Question

If n=12, ¯xx¯(x-bar)=40, and s=18, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population.

Give your answers to one decimal place. _______ < μ <_________

Answer 1

To construct a confidence interval at a 99% confidence level, use the formula: x-bar - z * (s / √n) for the lower bound and x-bar + z * (s / √n) for the upper bound.

Step-by-step explanation:

To construct a confidence interval at a 99% confidence level, we can use the formula:

Lower Bound: x-bar - z * (s / √n)

Upper Bound: x-bar + z * (s / √n)

Plugging in the given values, we have:

Lower Bound: 12 - 2.576 * (18 / √12) = 2.2

Upper Bound: 12 + 2.576 * (18 / √12) = 21.8

Therefore, the 99% confidence interval is: 2.2 < μ < 21.8