Null and Alternative Hypotheses

Question 1

you are measuring the difference between a sample average and the average of a standardized population; your computed t is 1.56 and your critical t from Appendix B is 2.56

what is your null? do you accept or reject it?

Answer 1

Ho: sample mean = population mean

accept the null because the computed t is less than the critical t

Question 2

you are measuring the difference between the average of a group that is independent than that of another group’s average; your computed t is 2.064 and your critical t from Appendix B is also 2.064

what is your null? do you accept or reject it?

Answer 2

Ho: independent sample mean = other independent sample mean

reject the null because the computed t is equal compared to the critical t

Question 3

you are measuring the difference between a group of students’ test a score and their test b score (which was administered six months after test a); your computed t is 4.74 and your critical t from Appendix B is 2.16

what is your alternative hypothesis? do you accept or reject it?

Answer 3

Ha1: mean test a score

Question 4

the smaller the t….

Answer 4

the greater the uncertainty

Question 5

What do you need to know to enter Appendix B?

Answer 5

degrees of freedom (df)
one tailed or two tailed test?
alpha level

Question 6

2 tailed

Answer 6

no prior research, cannot assume 1 alternative is illogical or impossible to achieve

Question 7

1 tailed

Answer 7

pilot of other research demmonstrates that 1 alternative is impossible or illogical