Chi-squared test
Equation: x2 = ∑(O – E)2/E
Question 1 – B codes for a black fur colour in gerbils, where as b codes for brown fur colour.
In a cross between two heterozygous gerbils, 29 black coated gerbils were produced and 7
brown coated gerbils were produced. Write a null hypothesis for this, show the cross and
carry out a chi-squared test to investigate the null hypothesis.
Null hypothesis: _____________________________________________________________
___________________________________________________________________________
Cross:
Chi-squared test:
O
E
O-E
(O-E)2
(O-E)2/E
Black
Brown
∑=
Response:
Question 2 – A codes for green peas and a codes for yellow peas. B codes for smooth peas,
where as b codes for wrinkled peas. In a cross between two double heterozygous pea
plants, 34 green smooth, 18 green wrinkled, 15 yellow smooth and 3 yellow wrinkled peas
were produced. Write a null hypothesis for this, show the cross and carry out a chi-squared
test to investigate the null hypothesis.
Null hypothesis: _____________________________________________________________
___________________________________________________________________________
Cross:
Chi-squared test:
O
E
O-E
(O-E)2
(O-E)2/E
∑=
Response:
Question 3 – A player roles a dice and gets the following numbers. Write a null hypothesis
for this and carry out a chi-squared test to investigate the null hypothesis.
Null hypothesis: _____________________________________________________________
___________________________________________________________________________
Chi-squared test:
O
10
11
9
7
14
12
E
O-E
(O-E)2
(O-E)2/E
∑=
Response: