Question

A company that makes language learning software wants to determine which of two approaches (Method A or Method B) to learning vocabulary would lead to the largest number of recalled words. The company wishes to evaluate the methods on 7 different languages (since languages differ in difficulty). Seven individuals, one per language, were recruited to learn words using Method A, and 7 individuals, one per language, were recruited to learn words using Method B.

Suppose the company wishes to test whether there is a difference in the two methods at the 0.05 level. Which of the following value(s) would correctly mark the boundary of the rejection region? Select all that apply!

		-2.447
		2.365
		1.895
		1.96
		2.447
		-1.96

Answer 1

Correct option : -2.447 and 2.447

Reason : degree of freedom = minimum ( n1-1 , n2 -1 ) = minimum( 7-1, 7-1 ) = 6

So, critical value = t _{6,alpha = 0.05} = t _6,0.05 = 2.447  

critical value = t _{6,alpha = 1 - 0.05} = t_6,0.95 = -2.447