题目
Bill owns a restaurant.
Over the next four weeks Bill decides to carry out a sample survey to obtain the customers’ opinions.
(a) Suggest a suitable sampling frame for the sample survey.
(b) Identify the sampling units.
(c) Give one advantage and one disadvantage of taking a census rather than a sample survey.
Bill believes that only 30% of customers would like a greater choice on the menu.
He takes a random sample of 50 customers and finds that 20 of them would like a greater choice on the menu.
(d) Test, at the 5% significance level, whether or not the percentage of customers who would like a greater choice on the menu is more than Bill believes. State your hypotheses clearly.
(Total for Question 2 is 9 marks)
题目中文翻译
Bill 拥有一家餐厅。
在接下来的四周里，Bill 决定进行抽样调查以获取顾客的意见。
(a) 建议一个适合此抽样调查的抽样框架。
(b) 识别抽样单位。
(c) 给出普查而非抽样调查的一个优点和一个缺点。
Bill 认为只有 30% 的顾客希望菜单有更多选择。
他随机抽取了 50 名顾客样本，发现其中 20 人希望菜单有更多选择。
(d) 在 5% 的显著性水平下，检验希望菜单有更多选择的顾客比例是否大于 Bill 的预期。清楚地陈述你的假设。
（第 2 题共 9 分）