Question

The following table gives the frequency distribution of married women by age at marriage:

Age (in years)	Frequency	Age (in years)	Frequency
15−19 20−24 25−29 30−34 35−39	53 140 98 32 12	40−44 45−49 50−54 55−59 60 and above	9 5 3 3 2

Calculate the median and interpret the results.

Answer 1

Here, the frequency table is given in inclusive form. So, we first transform it into exclusive form by subtracting and adding h/2 to the lower and upper limits respectively of each class, where h denotes the difference of lower limit of a class and upper limit of the previous class.

We have, N = 357
So, N/2 = 178.5

Thus, the cumulative frequency just greater than 178.5 is 193 and the corresponding class is 19.5−24.5.

Therefore, 19.5−24.5 is the median class.

Here, l = 19.5, f = 140, F = 193 and h = 5

We know that

$$\begin{gathered} =19.5+\left(\frac{178.5-53}{140}\right)\times 5 \\ =19.5+\frac{125.5}{140}\times 5 \\ =19.5+\frac{125.5}{28} \\ =\frac{546+125.5}{28} \\ =23.98 \end{gathered}$$

Hence, the median age 23.98 years.

Thus, nearly half the women were married between the age of 19.5 years and 24.5 years.