Answer :
Using a calculator, the critical value for the t-distribution, with a confidence level of 99%, a sample size n = 20 and a two-tailed test is of Tc = 2.8609.
How to find the critical value of the t-distribution?
It is found using a calculator, with three inputs, which are given by:
- The confidence level.
- The number of degrees of freedom, which is one less than the sample size.
- The tail.
In this problem, the inputs are given as follows:
- Confidence level of 99%, as 1 - 0.01 = 0.99 = 99%.
- 19 df, as 20 - 1 = 19.
- Two-tailed test, as stated in this problem.
Hence, using a calculator, the critical value is of is of Tc = 2.8609.
More can be learned about the t-distribution at brainly.com/question/27125917
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