Question

The scores on a math test are normally distributed with a mean of 80 and a standard deviation of 9. If a sample of 100 students' scores is taken, calculate the margin of error for a 95% confidence level.

2.2
1.8
1.6
2.0

Answer 1

1.8

Explanation:

Margin of Error = Critical Value * (Standard Deviation / √Sample Size)

For a 95% confidence level, the critical value is 1.96.

Next, we need to find the standard deviation. Given that the standard deviation of the scores is 9, we can use this value.

Finally, we need to find the square root of the sample size. The sample size is 100, so the square root of 100 is 10.

Margin of Error = 1.96 * (9 / 10) = 1.764

1.8 is closest to 1.764 so we will choose 1.8 as the answer