A farmer would like to know if a new fertilizer increases his crop yield. In an effort to decide this, the farmer recorded the yield for 9 different fields prior to adding fertilizer and after adding the fertilizer. The farmer assumes the crop yields are approximately normal. Does the fertilizer work as advertised? g

Explanation:

In the given question, the farmer wanted to study that if he will add a new fertilizer, the yield of the crop will be affected?

For this, he added the fertilizer in nine different plots and observed the yield which was found to be normal before and after the fertilizer was added.

This shows there is not a significant difference in the yield of the growth so to measure the significant difference, the average of the nine plots will be taken and then will be analyzed by the t-test.

Based on the t-test, the results will be concluded but in the given case the fertilizer does not work as no significant yield difference is observed.

the answer for this question would be d. glaciers

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: