Question

A sample size of 63 is drawn from a population whose standard deviation is 27, what is the margin of error for a 90% confidence interval?

a) 3.97
b) 4.32
c) 5.05
d) 6.22

Answer 1

The margin of error for a 90% confidence interval with a sample size of 63 and a population standard deviation of 27 is approximately 4.32.

Step-by-step explanation:

The margin of error for a 90% confidence interval can be calculated using the formula:

margin of error = Z * (standard deviation / sqrt(sample size)),

where Z is the critical value for a 90% confidence interval. In this case, Z is approximately 1.645. Given that the population standard deviation is 27 and the sample size is 63, we can calculate the margin of error as follows:

margin of error = 1.645 * (27 / sqrt(63)) ≈ 4.32.

Therefore, the margin of error for a 90% confidence interval is approximately 4.32.