Question

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

Answer 1

Margin of error = 16.5

Explanation:

The formula for the margin of error is given by :

`M=z* (\sigma)/(\sqrt n)`

We have, z (for 90% confidence interval) = 1.65

σ = 50 and n = 25

Putting all the values in the above formula, we get :

`M=1.65* \frac{50}{\sqrt {25}}\\\\M=16.5`

So, the margin of error for a 90% confidence interval is 16.5.