If the median of the distribution given below is $28.5,$ find the values of $x$ and $y$.
Class intervalFrequency
$0-10$$5$
$10-20$$x$
$20-30$$20$
$30-40$$15$
$40-50$$y$
$50-60$$5$
Total$60$

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(A) The cumulative frequency for the given data is calculated as follows:
Class intervalFrequencyCumulative frequency
$0-10$$5$$5$
$10-20$$x$$5+x$
$20-30$$20$$25+x$
$30-40$$15$$40+x$
$40-50$$y$$40+x+y$
$50-60$$5$$45+x+y$

From the table,the total frequency $n = 60$.
Thus,$45+x+y = 60 \implies x+y = 15 \dots (1)$.
The median is $28.5$,which lies in the class interval $20-30$.
Therefore,the median class is $20-30$.
Lower limit $(l) = 20$,frequency $(f) = 20$,cumulative frequency $(cf) = 5+x$,and class size $(h) = 10$.
Using the median formula: $\text{Median} = l + \left( \frac{\frac{n}{2} - cf}{f} \right) \times h$.
$28.5 = 20 + \left( \frac{30 - (5+x)}{20} \right) \times 10$.
$8.5 = \frac{25-x}{2}$.
$17 = 25 - x \implies x = 8$.
Substituting $x=8$ into equation $(1)$: $8+y = 15 \implies y = 7$.
Thus,$x = 8$ and $y = 7$.

Explore More

Similar Questions

In a retail market,fruit vendors were selling mangoes kept in packing boxes. These boxes contained varying numbers of mangoes. The following was the distribution of mangoes according to the number of boxes.
Number of mangoes$50$-$52$$53$-$55$$56$-$58$$59$-$61$$62$-$64$
Number of boxes$15$$110$$135$$115$$25$

Find the mean number of mangoes kept in a packing box. Which method of finding the mean did you choose?

Difficult
View Solution

The following table gives the production yield per hectare of wheat of $100$ farms of a village.
Production yield (in kg/ha)Number of farms
$50-55$$2$
$55-60$$8$
$60-65$$12$
$65-70$$24$
$70-75$$38$
$75-80$$16$

Change the distribution to a 'more than type' distribution,and draw its ogive.

$A$ survey conducted on $20$ households in a locality by a group of students resulted in the following frequency table for the number of family members in a household:
Family size$1-3$$3-5$$5-7$$7-9$$9-11$
Number of families$7$$8$$2$$2$$1$

Find the mode of this data.

The table below shows the daily expenditure on food of $25$ households in a locality.
Daily expenditure (in $Rs.$)$100-150$$150-200$$200-250$$250-300$$300-350$
Number of households$4$$5$$12$$2$$2$

Find the mean daily expenditure on food by a suitable method.

$A$ survey regarding the heights (in $cm$) of $51$ girls of Class $X$ of a school was conducted and the following data was obtained:
Height (in $cm$)Number of girls
Less than $140$$4$
Less than $145$$11$
Less than $150$$29$
Less than $155$$40$
Less than $160$$46$
Less than $165$$51$

Find the median height.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo