Explain it in English

Looking at the $f_i$ column, the highest frequency is 7.

The $x_i$ value that corresponds to the frequency of 7 is 7.
The mode is $\boxed{7}$.

The mean ($\bar{x}$) is calculated by dividing the sum of the products $x_i f_i$ by the sum of the frequencies $f_i$.

From the table:
$\sum x_i f_i = 138$
$\sum f_i = 20$

The mean is $\boxed{6.9}$.

The total number of observations is $N = \sum f_i = 20$.
Since $N$ is an even number, the median is the average of the $\frac{N}{2}$-th and $(\frac{N}{2}+1)$-th values.

So, we need to find the 10th and 11th values.

Using the calculated cumulative frequency (CF) column:

• The first 2 values are 2.
• The values from the 3rd to the 3rd are 4.
• The values from the 4th to the 8th are 6.
• The values from the 9th to the 15th are 7. Therefore, the 10th value is 7. And the 11th value is also 7. The median is the average of these two values:

The median is $\boxed{7}$.