Chi Square

Find the degrees of freedom.

• 4
• 5
• 6
• 7

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

• .50
• .10
• .05
• .01

How do you find degrees of freedom?

• one less than the possible genotypes
• one less than the possible phenotypes
• total number divided 2
• total number times 2

How do you find critical value?

• where degrees of freedom lines up with significance level
• where significance level lines up with chi-square
• the difference between total and chi-square 
• degrees of freedom minus significance level

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: 
observed 20 squares    expected : 18
observed 30 triangles   expected: 30
What is the expected number for circles?

• 6
• 12
• 18
• 24

Tags

NGSS.HS-LS3-3

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 degrees of freedom?

• 1
• 2
• 3
• 4

Tags

NGSS.HS-LS3-3

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

Tags

NGSS.HS-LS3-3

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

NGSS.HS-LS3-3

What is the

χ² _calculated value for the following situation.

• 6.65

• 6.66

• 0.00991

• 1

Tags

NGSS.HS-LS3-3

If we are testing at a 5% significance level and our p-value is 0.00453, what is the conclusion?

• Accept Null Hypothesis

• Reject Null Hypothesis

• We need to know chi-squared

• You cannot do this problem without a calculator