Question

An experiment was conducted to compare broadleaf seedling growth by treating the seedling soil weeds with one of two fertilizers. Thirty of 75 seedlings were randomly chosen to receive Fertilizer X. The rest received Fertilizer Y. The heights were recorded for each seedling, in centimeters, at the end of the study. The results obtained are shown.

Fertilizer X: X̄₁ = 72.4 cm, s₁ = 9 cm
Fertilizer Y: X̄₂ = 86.1 cm, s₂ = 8 cm

We wish to determine whether there is a difference in height for the seedlings treated with the different herbicides. To answer this question, we decide to test the hypotheses H₀: μ₂ − μ₁ = 0 and H_a: μ₂ − μ₁ ≠ 0. Find the 95% confidence interval for μ₂ − μ₁ and make a conclusion based on that confidence interval.

A. The 95% confidence interval is 13.7 ± 4.065. I would not reject the null hypothesis of no difference at the 0.05 level.

B.The 95% confidence interval is 13.7 ± 9.63. I would not reject the null hypothesis of no difference at the 0.05 level.

C. The 95% confidence interval is 13.7 ± 4.065. I would reject the null hypothesis of no difference at the 0.05 level

D. The 95% confidence interval is 13.7 ± 9.63. I would reject the null hypothesis of no difference at the 0.05 level.

E. The 95% confidence interval is 13.7 ± 17.75. The p-value is less than 0.05.

Answer 1