Q 8.3RP. - Elementary Statistics

Question

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

Step-by-Step Solution

Answer

No.

Step 1: 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.

Step 2: Understand the problem and identify the approach

Read the problem carefully and determine what techniques are needed.

Step 3: Set up and execute the solution

Translate the problem into mathematical expressions and apply techniques.

Step 4: Compute and simplify

Perform calculations and simplify.

Step 5: State the final answer

Present the final answer.