Hypothesis Tests

Question 1

What is the null hypothesis of a chi-square test?

Answer 1

H₀: One variable is independent of the other variable

Question 2

What are the steps to running a chi-square test of independence on your GDC?

Answer 2

1. Create and name a matrix
2. Run a X² 2-way Test.

Question 3

How can you tell how many degrees of freedom your test will have?

Answer 3

You look at the number of rows and columns in the matrix (not including the totals).

degrees of freedom = (rows -1) * (columns -1)

OR

Question 4

How do you find the expected frequency?

Answer 4

Multiply the two probabilities and the total number of students.

Question 5

What is the critical value for a X² test of independence?

Answer 5

It’s the cut-off point. It tells you where you make the decision to reject or not reject the null hypothesis.

Question 6

How do you find the critical value on your GDC?

Answer 6

1. Use the “inverse X2” feature of the GDC.
   area = 1 - significance level.

Question 7

How do you use the critical value to make a decision about your test (reject/not reject)?

Answer 7

Reject if statistic > critical value

Question 8

How do you use the p-value to make a decision about your test (reject/not reject)?

Answer 8

Reject if p < significance level