题目
Each day a restaurant opens between 11 am and 11 pm. During its opening hours, the restaurant receives calls for reservations at an average rate of 6 per hour.
(a) Find the probability that the restaurant receives exactly 1 call for a reservation between 6 pm and 7 pm.
The restaurant distributes leaflets to local residents to try and increase the number of calls for reservations. After distributing the leaflets, it records the number of calls for reservations it receives over a 90 minute period.
Given that it receives 14 calls for reservations during the 90 minute period,
(b) test, at the 5% level of significance, whether the rate of calls for reservations has increased from 6 per hour. State your hypotheses clearly.
题目中文翻译
每天一家餐厅从上午 11 点营业到晚上 11 点。在营业时间内，该餐厅接到预订电话的平均速率为每小时 6 个。
(a) 求餐厅在下午 6 点到 7 点之间恰好接到 1 个预订电话的概率。
(b) 餐厅向当地居民分发传单，试图增加预订电话的数量。发放传单后，它记录了在 90 分钟内接到的预订电话数量。
已知在这 90 分钟内接到 14 个预订电话。
在 5% 显著性水平下检验：预订电话的到达速率是否从每小时 6 个增加了。清楚写出假设。