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

Answer:

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

Step-by-step 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 =

$z_{critical}\times \dfrac{\sigma}{\sqrt{n}}$

Putting the values, we get,

$1.64\times \dfrac{50}{\sqrt{25}} = 16.4$

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