累积频数图像显示了 2022 年首 120 名完成马拉松的跑者的用时分布。 该箱线图表示了 2023 年首 120 名完成马拉松的跑者的用时分布。 利用这两个图表完成关于这两场马拉松的表格。 Simon 说 2022 年的跑者平均而言更快捷。你同意吗？请给出你的理由。 完成下方关于 2023 年跑者的频数表。

1. Compare the average finishing times using the medians

For 2022, the median time is $154.5$ minutes.

From the 2023 box-and-whisker plot, the median time is about $150$ minutes.

Since $154.5>150$, the typical runner in 2022 took longer, so the runners in 2022 were not quicker on average.

1. Find the frequency for $140<t\leq145$ using the lower quartile

There are $120$ runners, so the lower quartile is the $\dfrac{120}{4}=30$th value.

For 2023, the lower quartile is $145$ minutes, so $30$ runners have times $t\leq145$.

Given $4$ runners have $135<t\leq140$,
$\text{frequency for }140<t\leq145=30-4=26.$

2. Find the frequency for $155<t\leq160$ using the upper quartile and total frequency

The upper quartile is the $\dfrac{3}{4}\times120=90$th value.

For 2023, the upper quartile is $155$ minutes, so $90$ runners have times $t\leq155$.

Hence the number of runners with $t>155$ is
$120-90=30.$

Given $9$ runners have $160<t\leq165$,
$\text{frequency for }155<t\leq160=30-9=21.$