SAT Question 3e1bd4e2: Inference From Sample Statistics And Margin Of Error answer and explanation with Desmos solution

Choice A is correct. It’s given that the mean length of fish in the sample was $16.59$ millimeters. It’s also given that based on the sample mean and margin of error, the researchers estimated that the mean length of all fish of this species from this location was between $15.86$ and $17.32$ millimeters. These values are calculated by subtracting the margin of error from $16.59$ millimeters to get the lower bound, $15.86$ millimeters, and by adding the margin of error to $16.59$ millimeters to get the upper bound, $17.32$ millimeters. It follows that the margin of error, in millimeters, can be calculated as the difference between $16.59$ and $15.86$ or between $17.32$ and $16.59$. The difference between $16.59$ and $15.86$ is $16.59-15.86$, or $0.73$. Therefore, the margin of error, in millimeters, is $0.73$.