chi-square-hypothesis-and-interpretation

HYPOTHESIS: If the observed numbers of tall and short plants are consistent with a 3:1 ratio, then there will be a chi square value < the critical value.

Interpretation Greater differences between expected and observed data produce a larger Chi-square value. The larger the Chi-square value, the greater the probability that there really is a significant difference. (â&#x20AC;&#x153;Something else is going onâ&#x20AC;?)

1. If the Chi-square value is greater than or equal to the critical value then, there is a significant difference between the groups we are studying. That is, the difference between observed data and the expected data is probably too great to be attributed to chance. So we conclude that our data does not support the proposed hypothesis.

2. If the Chi-square value is less than the critical value then, there is no significant difference. The difference between expected and actual data is likely just due to random chance.

Thus, we conclude that our data does support the proposed hypothesis.

Conclusion.

In this example, the critical value is 3.8. The Chi-square value was 2.383, which is less than 3.8. Thus, there is no significant difference in the numbers of tall and short plants. We conclude that based on this sample, these plants show a simple dominance and recessive genetic inheritance pattern.