Question

Find the values of t that bound the middle 0.95 of the distribution for df = 20. (Give your answers correct to two decimal places.)_

_____ to _____

You may need to use the appropriate table in Appendix B to answer this question.

Answer 1

We have to find the t value that bound the middle 0.95 of the distribution with degree of freedom = 20

So, it is two tailed. We can find the significance level = (1-0.95)/2 = 0.05/2 = 0.025

So, we can either find t(0.025,20) for right tailed or we can find t(0.05,20) for two tailed. both will give same values

Using t distribution table for right tailed test, we get

t(0.025,20) = 2.09...............................{check df = 20 for alpha level 0.025}

So, right tailed t value is +2.09

we know that the distribution is symmetric, it will have same value on the left hand side with negative sign, i.e. t value for left hand tail = -2.09

So, values of t that bound the middle 0.95 of the distribution for df = 20 are -2.09 to +2.09