In one of Mendel's dihybrid crosses of peas, he observed round yellow, round green, wrinkled yellow, and wrinkled green F2 plants. He used the Chi Square test to see if the number of plants he observed in each category matched the expected 9:3:3:1 ratio. The Chi Square value he calculated was 6.15. Use the probability table below to determine the p-value. How should he interpret this p-value?
Degrees of Freedom | Probability (p-value)
--- | 0.95 | 0.90 | 0.80 | 0.70 | 0.50 | 0.30 | 0.20 | 0.10 | 0.05 | 0.01 | 0.001
1 | 0.004 | 0.02 | 0.06 | 0.15 | 0.46 | 1.07 | 1.64 | 2.71 | 3.84 | 6.64 | 10.83
2 | 0.10 | 0.21 | 0.45 | 0.71 | 1.39 | 2.41 | 3.22 | 4.60 | 5.99 | 9.21 | 13.82
3 | 0.35 | 0.58 | 1.01 | 1.42 | 2.37 | 3.66 | 4.64 | 6.25 | 7.82 | 11.34 | 16.27
4 | 0.71 | 1.06 | 1.65 | 2.20 | 3.36 | 4.88 | 5.99 | 7.78 | 9.49 | 13.28 | 18.47
Any variation of his data from the 9:3:3:1 ratio may be expected by chance and are not significant; do not reject the hypothesis.
These data are significantly different from the 9:3:3:1 ratio; reject the hypothesis.