Question

-Wing spans were measured for a random sample from a population of wasps: 4.9, 3.6, 5.7, 5.3, 4.2, 4.1, 5.6, 5.2 cm.

Find a 95% confidence interval for the mean wing span.
3) What is the critical value t?
A. 1.895
b. 2.306
C.2.365
D. 1.812

Answer 1

Explanation:

To find the critical value t for a 95% confidence interval, we need to determine the degrees of freedom (df) and refer to the t-distribution table.

In this case, since we are working with a small sample size, we use the t-distribution rather than the z-distribution. The formula to calculate the degrees of freedom for a sample is (n - 1), where n is the sample size.

Given the sample data, we have a sample size of 8. Therefore, the degrees of freedom (df) would be (8 - 1) = 7.

Now, we can refer to the t-distribution table or use statistical software to find the critical value t at a 95% confidence level and 7 degrees of freedom.

Looking at the t-distribution table, the closest critical value to a 95% confidence level with 7 degrees of freedom is approximately 2.365.

Therefore, the correct answer is C. 2.365.

Answer 2

The answer is B. 2.306.