题目
A manufacturer makes t-shirts in 3 sizes, small, medium and large.
20% of the t-shirts made by the manufacturer are small and sell for £10
30% of the t-shirts made by the manufacturer are medium and sell for £12
The rest of the t-shirts made by the manufacturer are large and sell for £15
(a) Find the mean value of the t-shirts made by the manufacturer.
A random sample of 3 t-shirts made by the manufacturer is taken.
(b) List all the possible combinations of the individual selling prices of these 3 t-shirts.
(c) Find the sampling distribution of the median selling price of these 3 t-shirts.
(Total for Question 4 is 10 marks)
题目中文翻译
一家制造商生产3 种尺码的 T 恤：小号、中号和大号。
• 该制造商生产的20% 的 T 恤是小号，售价为 10 英镑
• 该制造商生产的30% 的 T 恤是中号，售价为 12 英镑
• 其余的 T 恤是大号，售价为 15 英镑
(a) 求该制造商生产的 T 恤的平均价值。
随机抽取该制造商生产的3 件 T 恤作为样本。
(b) 列出这3 件 T 恤个体售价的所有可能组合。
(c) 求这3 件 T 恤中位数售价的抽样分布。
（第 4 题共 10 分）