Question: You investigate whether the older or younger male in pairs of brothers tends to be more extroverted. You obtain the following extroversion scores:

Sample 1 (Younger) Sample 2 (Older)
10 18

11 17

18 19

12 16

15 15

13 19

19 13

15 20

a) What is the null hypothesis and alternative hypothesis?
b) Compute obtained value in t-test
c) With the theoretical probability of a type 1 error= .05, what is the critical value of t-test?
d) What should you conclude about this relationship?
e) Which of our approaches should we use to determine if this is a scientifically important relationship?