a.Find the margin of error E for a 90% confidence interval. (5 points)
Round your answer to the nearest hundredths. .
Margin of error = (z-value)(sd/√n)
Find the z-value using the z-table for 90% confidence. You will need the standard deviation and the sample size to finish the calculation.
To find the margin of error, E, for a 90% confidence interval, you'll need to know the sample size and the standard deviation.
The formula to calculate the margin of error is:
E = Z * (σ / √n)
Where:
E: Margin of error
Z: Z-score (corresponding to the desired confidence level)
σ: Standard deviation
n: Sample size
For a 90% confidence level, the corresponding Z-score is approximately 1.645 (you can find this value in a standard normal distribution table or use software like Excel or statistical calculators to obtain it).
Assuming you have the sample size, n, and the standard deviation, σ, you can substitute these values into the formula to calculate the margin of error, E.
Remember to round your answer to the nearest hundredths as specified.
If you don't have the sample size or the standard deviation, you will need to gather more information or use some statistical techniques to estimate these values.