题目
Amala believes that the resting heart rate is lower in men who exercise regularly compared to men who do not exercise regularly. She measures the resting heart rate, , of a random sample of 50 men who exercise regularly and a random sample of 40 men who do not exercise regularly. Her results are summarised in the table below.
| Sample | Sample size | Unbiased estimate of the mean | Unbiased estimate of the variance | ||
|---|---|---|---|---|---|
| Exercise regularly | 50 | 3270 | 214676 | ||
| Do not exercise regularly | 40 | 2832 | 201660 | 70.8 | 29.6 |
(a) Calculate the value of and the value of
(b) Test, at the 5% level of significance, whether there is evidence to support Amala’s belief. State your hypotheses clearly.
(c) Explain the significance of the central limit theorem to the test in part (b).
(d) State two assumptions you have made in carrying out the test in part (b).
题目中文翻译
Amala 认为,与不经常锻炼的男性相比,经常锻炼的男性静息心率更低。她测量了一组 50 名经常锻炼男性和一组 40 名不经常锻炼男性的静息心率 。结果汇总如下表。
| 样本 | 样本量 | 均值的无偏估计 | 方差的无偏估计 | ||
|---|---|---|---|---|---|
| 经常锻炼 | 50 | 3270 | 214676 | ||
| 不经常锻炼 | 40 | 2832 | 201660 | 70.8 | 29.6 |
(a) 求 的值和 的值。
(b) 在 5% 显著性水平下检验:是否有证据支持 Amala 的看法。清楚写出假设。
(c) 解释中心极限定理在 (b) 中检验的意义。
(d) 写出你在 (b) 中进行检验时作出的两个假设。