下面的背靠背茎叶图表示 $A$、$B$ 两家公司各 27 名员工的月薪，单位为元。

(a) 求公司 $A$ 员工月薪的中位数和四分位距。

公司 $B$ 月薪的下四分位数、中位数和上四分位数分别为 $2600、$2690 和 $2780。

(b) 在同一幅图中画出两个箱线图，表示公司 $A$ 和 $B$ 员工月薪的数据。

(c) 说明在比较这两家公司的给定数据时，均值是否是比中位数更合适的度量。

Answer all questions. You should use a calculator where appropriate.

You must show all necessary working clearly; no marks will be given for unsupported answers from a calculator.

Give non-exact numerical answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless a different level of accuracy is specified in the question.

请回答所有题目。适当时应使用计算器。必须清楚展示所有必要的计算过程；仅给出计算器答案而没有过程，不予评分。除非题目另有精度要求，非精确数值答案保留 3 位有效数字，以度为单位的角度保留 1 位小数。

27个薪资的中位数第14项、四分位数第7与第21项，注意图例每个叶单位为10元。

For company A, the 14th ordered salary is 2710 dollars, so the median is 2710 dollars.

The 7th and 21st salaries are 2610 and 2840 dollars. Hence

从原图读最小最大值，与给定或(a)所得四分位数画共用刻度箱线图。

Use the five-number summaries, in dollars:

Draw the boxes from the lower to upper quartiles, marking their medians, and extend whiskers to the minimum and maximum. Use a shared linear axis labelled “Monthly salary (dollars)” and label each company.

公司B有一笔3090的极端高薪，会影响均值，故中位数更适合比较。

No. The median is more appropriate, because company B has an unusually high salary of 3090 dollars, which would raise its mean and make it less representative of typical salaries.