Aces 和 Jets 两支队伍各有 11 名队员，他们的身高（单位为厘米）如下表所示。

(a) 画一幅背靠背茎叶图表示这些数据，将 Aces 队的数据放在图的左侧。

(b) 求 Aces 队队员身高的中位数和四分位距。

(c) 就 Aces 队与 Jets 队队员身高的离散程度作出一项比较。

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。

身高十位及百位构成茎16至19，个位作叶；左Aces从茎向外递增，键值解释两队与厘米单位。

Use stems $16,17,18,19$, with Aces on the left and Jets on the right. Order leaves away from the stem on both sides.

Key: $1\mid17\mid0$ means 171 cm for the Aces and 170 cm for the Jets.

11个数据的中位数第6项、四分位数第3与第9项。

The ordered Aces heights are

The median is the 6th value, 173 cm. The lower and upper quartiles are the 3rd and 9th values, 168 cm and 181 cm. Thus

只比较题目要求的离散程度。Jets四分位距188−170=18，比Aces的13大。

The Jets have a greater spread of heights: their interquartile range is $188-170=18$ cm, compared with 13 cm for the Aces.