Question

Find the margin of error for a 90% confidence interval when the standard deviation is LaTeX: \sigma= 50????=50 and LaTeX: n = 25????=25. (Round to three decimal places.)

Answer 1

The margin of error for a 90% confidence interval is 16.4

Explanation:

We are given the following in the question:

Sample size, n = 25

Standard deviation = 50

`z_(critical)\text{ at}~\alpha_(0.10) = \pm 1.64`

Margin of error =

`z_(critical)* (\sigma)/(√(n))`

Putting the values, we get,

`1.64* (50)/(√(25)) = 16.4`

Thus, the margin of error for a 90% confidence interval is 16.4