下面的累积频数图显示了某学校 240 名学生的体重。 利用该图求：

1. Find the number of students with weight greater than 55 kg

From the cumulative frequency graph, the number of students with weight $\leq 55$ kg is approximately $238$.

Total number of students $=240$.

Number with weight $>55$ kg:
$240-238=2$

1. Identify the effect of adding 5 kg to every recorded weight

Each corrected weight is
$\text{recorded weight} + 5$ kg.

So a student recorded at weight $x$ kg will be shown at corrected weight $(x+5)$ kg.

2. Describe how the cumulative frequency curve changes

The number of students is unchanged, so the cumulative frequencies stay the same.

Only the horizontal weight values increase by $5$ kg. Hence the curve is shifted $5$ kg to the right, with the same shape.