chi-square test and expected count

Which significance level  
(column) do you look at when finding the critical value?

• .50
• .10
• .05
• .01

Tags

CCSS.HSS.ID.A.4

How do you find degrees of freedom?

• Number of values subtract 1

• total number divided 2

• total number times 2

How do you find the expected count?

• Probability subtracted by the observed value

• Probability divided by the total number of trials

• Probability multiplied by the observed value

• Probability multiplied by the total number of trials

Tags

CCSS.HSS.MD.A.2

Observed in the wild are 10 circles, 20 squares and 30 triangles. The ratio for this particular population is 20%, 30%, and 50%. 

observed 20 squares    expected : 18

observed 30 triangles   expected: 30

What is the expected number for circles? (Hint: Prob x total)

• 6

• 12

• 18

• 2

Observed in the wild are 10 circles, 20 squares and 30 triangles. The ratio for this particular population is 20%, 30%, and 50%. 

observed: 10 circles     expected: 12

observed 20 squares    expected : 18

observed 30 triangles   expected: 30

What is the degrees of freedom?

• 1

• 2

• 3

• 4

Observed in the wild are 10 circles, 20 squares and 30 triangles. The ratio for this particular population is 2:3:5 
observed: 10 circles     expected: 12
observed 20 squares    expected : 18
observed 30 triangles   expected: 30
What is the critical value?

• 3.841

• 5.991

• 7.815

• 9.488

Observed in the wild are 10 circles, 20 squares and 30 triangles. The ratio for this particular population is 2:3:5 
observed: 10 circles     expected: 12
observed 20 squares    expected : 18
observed 30 triangles   expected: 30
What is the X² of this problem?

• .22

• .33

• .44

• .55

Observed in the wild are 10 circles, 20 squares and 30 triangles. The ratio for this particular population is 2:3:5 
observed: 10 circles     expected: 12
observed 20 squares    expected : 18
observed 30 triangles   expected: 30
Would you accept or reject?

• accept
• reject

Tags

CCSS.7.SP.A.2