In a dihybrid cross, a researcher obtained the following results. He wondered whether his results could be considered as
9:3:3:1 ratio. Help him solve the problem. Make sure to make a null hypothesis, show how you calculated your chi-square
results, and give a conclusion using the chi-square probability table provided.
Expected
ratio
9 3 3 1 Total
Expected
900 300 300 100 1600
Observed
1250 150 150 50 1600
Degrees of
Freedom
1234567
789100
0.71
1.06
0.95 0.90 0.80 0.70 0.50 0.30
0.004 0.02 0.06 0.15 0.46 1.07
0.10 0.21 0.45 0.71 1.39 2.41
0.35 0.58 1.01 1.42 237 3.66
1.65 2.20 3.36
Table 5.3. Chi-square value
Probability
Non- Signi- Highly
significant ficant significant
0.20 0.10 0.05 0.01
1.64 2.71 3.84 6.64
3.22 4.60 5.99 9.21
11.34
6.25
4.64
7.82
4.88
5.99 7.78 9.49
13.28
1.14
1.61
2.34 3.00
435
6.06
7.29 9.24 11.07
15.09
1.63
2.20 3.07 3.83
5.35 7.23
8.56 10.64 12.59 16.81
2.17
3.82 2.83
4.67
6.35 8.38
9.80 12.02 14.07
18.48
2.73
3.49
4.59
5.53
734 9.52 11.03 13.36 15.51
20.09
3.32 4.17
5.38 6.39
834 10.66 12.24 14.68 16.92
21.67
3.94 4.86
6.18
7.27
934 11.78 13.44 15.99 18.31 23.21