Question

which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a the swimmers had faster times on average in the final round. b the times in the final round vary noticeably more than the times in the semifinal round. c none of the above

Explanation:

To determine the correct answers, we analyze each option:

• Option A: If the dot plot for the final round has a lower average (since lower swim times are faster), then the swimmers had faster times on average in the final round. This is a valid interpretation of dot plots (comparing central tendency).
• Option B: To check variability, we look at the spread of dots. If the final round's dot plot is more spread out (wider range or more dispersion) than the semifinal, then times vary more. But typically, in such swim time scenarios, finals often have less variability (more consistent, faster times) or similar, so this is less likely. However, the key is to assess based on dot plot interpretation. But for the sake of the question, let's assume the dot plots show that the final round has a lower average (so A is correct), and B is incorrect (since usually finals have less variation or similar, not more). Wait, but maybe the actual dot plots (not shown here) could have A correct. Since the problem is about dot plots (a statistical tool), we analyze:

For A: Faster times (lower values) on average in final round – if the final round's dot plot is shifted left (lower values) than semifinal, then average is lower (faster). So A is a valid info from dot plots (comparing means/medians).

For B: Variability – if final round's dots are more spread, then B is correct, else not. But since the problem is a multiple-choice with A as a possible correct (assuming the dot plots show final round has lower average), and B is not (since "noticeably more" variation is unlikely in finals). But the standard interpretation:

If we assume the dot plots (even though not shown) have final round with lower average (faster times), then A is correct. B is incorrect because usually, in competitive swimming, final round times are more consistent (less variation) or similar, not more. So A is correct.

Answer:

A. The swimmers had faster times on average in the final round.