一个有10名男生和10名女生的班级进行了一次测试。
女生的分数分别是 4, 5, 6, 7, 7, 7, 8, 8, 8 和 10。

它不会直接告诉你答案，而是问你卡在哪一步看看 AI 是怎么陪你一步步弄懂这道题的

完整解法

1. Find the most frequent mark(s) in the girls' marks

Girls' marks: $4, 5, 6, 7, 7, 7, 8, 8, 8, 10$ .

$7$ occurs $3$ times and $8$ occurs $3$ times, more than any other mark.

So the modal marks are $7$ and $8$ .

答案

$7$ and $8$

1. Calculate the mean mark for the girls

$\text{Mean} = \frac{4+5+6+7+7+7+8+8+8+10}{10}=\frac{70}{10}=7$

答案

$7$

1. Find the boys' mean mark using the whole-class mean and the girls' mean

There are $20$ students in total.

Total mark for whole class:
$20 \times 7.5 = 150$

Total mark for girls from part (b):
$10 \times 7 = 70$

Total mark for boys:
$150 - 70 = 80$

Mean mark for boys:
$80 \div 10 = 8$

2. Compare the boys' mean with the girls' mean and justify the claim

Boys' mean $= 8$ and girls' mean $= 7$ .

Since $8 > 7$ , the boys did better on average.

答案

Yes. The boys' mean mark was $8$ , which is higher than the girls' mean mark of $7$ .

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