Question

A school of fish Refer to Exercise 74.

a. Explain why it was necessary to inspect a graph of the sample data when checking the Normal/Large Sample condition.

b. According to the packaging, there are supposed to be $330$goldfish in each bag of crackers. Based on the interval, is there convincing evidence that the average number of goldfish is less than $330$? Explain your answer.

Short answer

a. This because sample size is small.

b. No evidence is present that average number of goldfish is less than$330$

Step-by-step solution

Given Information

Given data is:$317,330,325,323,332,337,324,342,330,349,335,330$

Necessity of inspecting graph

Sample data consists of $12<30$values. To make sure that normal/large condition is satisfied, inspecting graph of sample data is important.

Checking if there is evidence that average goldfish is <330

Output using excel is:

Required confidence interval is $325.596<\mu <336.738$.

The upper limit is higher than $330$.

There is no evidence that average goldfish is less than$330$