Choose the correct answer:

Problem 1:

A gardener knows from experience that sunflower seeds sprout and grow to an average height of 40 inches in 30 days. The gardener is concerned that a recent drought will affect the growth of the sunflower plants. From a large field of sunflower seeds planted by the gardener, a random sample of 40 sunflower plants was selected 30 days after planting. The average height of these sunflower plants was 38.4 inches with a standard deviation of 2.88 inches. At a 1% significance level, can the gardener conclude that, after 30 days from planting, the mean height of all sunflower plants in the field is less than 40 inches? Use both the p-value and the critical value approaches.

a. Yes, the gardener can conclude that, after 30 days from planting, the mean height of all sunflower plants in the field is less than 40 inches.

b. No, the gardener can not conclude that, after 30 days from planting, the mean height of all sunflower plants in the field is less than 40 inches.