Question

Chi-Square Data

	Brown Eyes Bushy Eyebrows	Brown Eyes Thin Eyebrows	Blue Eyes Bushy Eyebrows	Blue Eyes Thin Eyebrows
Observed	5	7	0	0
Expected	4.5	4.5	1.5	1.5

Show your Chi-Square Calculations below:

The p value from the analysis is _______.  The degrees of freedom are __________.

The results show (check on circle):

⃝

The Observed and Expected are significantly different

⃝

The Observed and Expected are not significantly different

Discuss what your results tell us about how these two genes are placed on the same chromosome.

Answer 1

Degrees of freedom formula = n-1

Where is n is the number of classes.

Therefore df= 4-1=3 .

$\chi 2$ =(Observed-expected)2/expected value.

= (5-4.5)2/4.5+(7-4.5)2/4.5+(0-1.5)2/1.5+(0-1.5)²/1.5

= 0.05+1.38+1.5+1.5=4.43

In a chi square table the p value is in between 0.25 and 0.10 at a level of significance is 0.05. since the p value is greater than the significance value then the null hypothesis is accepted.

By accepting the null hypothesis we can conclude that the two genes are placed on the same chromosome.