Question

Must the variable under consideration be normally distributed for you to use the z-interval procedure or $t-$interval procedure? Explain your answer.

Short answer

No.

Step-by-step solution

Explanation

No,

The $z-$interval or $t-$interval approach can be used to find the confidence interval of a population mean even if the variable under investigation is not normally distributed.

Because of the following conditions are met, we can apply the $z-$interval or $t-$interval technique for non-normally distributed variables.

• Large sample i.e, sample size $>30$
• The variable in question is near to being normally distributed, and there are no outliers in the sample data.