Question

The owner of a fish market has an assistant who has determined that the weights of catfish are normally​ distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. what percentage of samples of 4 fish will have sample means between 3.0 and 4.0​ pounds

Answer 1

21.72%
The 68-95-99 rule states that 1 standard deviation from the mean will contain 68% (68.27 more specifically) of all data points. For each sample, we multiply the success rate for .6827*.6827*.6827*.6827 =.2172 or 21.72%