Answer
In problem 19.16, we assumed a normal distribution; hence, the answer will change. However, in 19.17 & 19.18, the sample is sufficiently large, so according to Central Limit Theorem, the distribution of the mean will certainly be approximately normal, meaning the answers will not be affected.
Work Step by Step
In problem 19.16, we assumed a normal distribution; hence, the answer will change. However, in 19.17 & 19.18, the sample is sufficiently large, so according to Central Limit Theorem, the distribution of the mean will certainly be approximately normal, meaning the answers will not be affected.