[Campbell Biology P.353] After performing a chi-square test, you obtain a P value of 0.03. W... | Practice Question

After performing a chi-square test, you obtain a P value of 0.03. What does this P value mean, and what conclusion should you draw about your null hypothesis?

  • A: P > 0.05; do not reject the null hypothesis. The genes are likely unlinked.
  • B: P ≤ 0.05; reject the null hypothesis. There is evidence that the genes are linked.
  • C: P ≤ 0.05; accept the null hypothesis. The genes are unlinked.
  • D: P > 0.05; reject the null hypothesis. The genes are linked.

Explanation

The P value represents the probability that the observed deviation from the expected results could be due to random chance alone, assuming the null hypothesis is true. A P value of 0.03 or 3% is less than the standard alpha level of 0.05. This means there is a low probability that the observed results occurred by chance if the genes were unlinked. Therefore, we reject the null hypothesis and conclude that the deviation is statistically significant, providing evidence that the genes are likely linked.