Question

五个考试分数的平均数是 $90$ ，中位数是 $91$ ，众数是 $94$ 。最低的两个考试分数之和是

Five test scores have a mean (average score) of $90,$ a median (middle score) of $91,$ and a mode (most frequent score) of $94.$ The sum of the two lowest test scores is

$170$

$171$

$176$

$177$

由已给信息无法确定

not determined by the information given

答案：B

知识点：平均数中位数（数据）众数

难度评级：1060

解答：

五个分数总和为 $5 \times 90 = 450$ 。中位数是第三个分数 $91$ 。因为 $94$ 是众数，它至少出现两次，且这两次都在中位数以上，所以最高两个分数是 $94, 94$ 。

三个最高分是 $91, 94, 94$ ，和为 $279$ 。因此最低两个分数之和是 $450 - 279 = 171$ 。

所以正确答案是 B。

The five scores sum to $5 \times 90 = 450.$ The median is the third score, $91.$ Since $94$ is the mode, it must appear at least twice, and both copies lie above the median, so the two highest scores are $94, 94.$

The three highest scores are $91, 94, 94,$ summing to $279.$ So the two lowest sum to $450 - 279 = 171.$

Thus, the correct answer is B .

1992 AMC 8 第 13 题

答案：B

难度评级：1060

解答：

其他年份的第 13 题