Question

An experiment was conducted to compare grass seedling growth by treating the seedling soil with one of two fertilizers. Twenty-five of 100 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 = 56.2 cm, s1 = 8 centimeters
Fertilizer Y X̄2 = 64.5 cm, s2 = 7 cm

We wish to determine whether there is a difference in height for the seedlings treated with the different fertilizers by testing the hypotheses H0: μ2 − μ1 = 0 and Ha: μ2 − μ1 ≠ 0. Find the 90% confidence interval for μ2 − μ1 and make a conclusion based on that confidence interval.

Answer 1