Answer:
H₀ : μ = 400
Hₐ : μ > 400
Step-by-step explanation:
The null hypothesis, is the one where things are happenning as expected. There is no difference because of a lack of evidence to proove there will be an improvement. In this case, the implementation of the new fertilizer is expected to increase the mean number of punds of fruit produced, but they don't have any way to proove that this will happen, so it doesn't make any difference.
The alternative hypothesis, is the one where a change is expected to happen. In this case, the new fertilizer is expected to increase the number of punds of fruit on the plot because making changes on the production process, will give new results, that are hoped to be better.
*Notice, that these hypothesis are based on the expectation of improving the fruit production.