Let us find the median of length of diameter from the following frequency distribution table of length of diameter of pipe.

To find out median, we need to calculate cumulative frequency for the given data.

Let us make a table for that.

Here, n = 80, that is, n = even.

Since, n is even, median can be found out as:

⇒

⇒ Median = The mean of 40^th and 41^th observations

And we know that, 40^th observation = 22 [∵ 40 comes between 33 and 57]

And 41^th observation = 22 [∵ 41 comes between 33 and 57]

Median = Mean of 22 and 22

⇒

⇒

⇒ Median = 22

Thus, median = 22.