The lifetime of a certain brand of battery is known to have a standard deviation of 10.5

Question:

The lifetime of a certain brand of battery is known to have a standard deviation of 10.5 hours. Suppose that a random sample of 120 such batteries has a mean lifetime of 40.9 hours. Based on this sample, find the 95% confidence interval for the true mean lifetime of all batteries of this brand.
Fantastic news! We've Found the answer you've been seeking!

Step by Step Answer:

Related Book For  book-img-for-question
Question Posted: