Question

Find the 95% confidence interval using a two-tailed test

1. N = 19 S = 3.4 Mean = 15.3

2. N = 22 S = 2.9 Mean = 13.2

3. N = 5 S = 5.7 Mean = 46.7

4. N = 13 S = 7.2 Mean = 50.5

5. N = 26 S = 7.8 Mean = 39.4

Answer 1

To find the 95 percent confidence interval, we can use the formula: Confidence Interval = Mean ± Margin of Error. Using the given information, we can calculate the confidence intervals for the provided data.

Step-by-step explanation:

To find the 95 percent confidence interval, we need to use the formula:

Confidence Interval = Mean ± Margin of Error

Where:

• Mean is the sample mean
• Margin of Error is the critical value multiplied by the standard deviation divided by the square root of the sample size

Using the provided information, we can calculate the confidence intervals as follows:

1. Confidence Interval = 15.3 ± (1.960 * (3.4 / √19)) = (12.708, 17.892)
2. Confidence Interval = 13.2 ± (1.960 * (2.9 / √22)) = (10.709, 15.691)
3. Confidence Interval = 46.7 ± (1.960 * (5.7 / √5)) = (37.052, 56.348)
4. Confidence Interval = 50.5 ± (1.960 * (7.2 / √13)) = (44.279, 56.721)
5. Confidence Interval = 39.4 ± (1.960 * (7.8 / √26)) = (34.896, 43.904)