Question

You decide to increase your Utah county coronavirus sample to 10 counties and estimate the same sample standard deviation you did with your sample of 5 counties. This will ______________ the margin of error associated with your 90% confidence interval.

Answer 1

This will decrease the margin of error associated with your 90% confidence interval.

Explanation:

Margin of error:

The margin of error of a confidence interval is given by a formula that follows the following format:

`M = z(s)/(√(n))`

In which z is related to the confidence level, s is related to the standard deviation and n is related to the size of sample.

From the formula:

M and n are inversely proportional, which means that if the sample size is increased, the margin of error decreases.

In this question:

Sample size increases from 5 to 10, so the margin of error decreases.