Question

20-30,30-40,40-50,50-60,60-70,70-80,80-90 frequency 5,15,25,20,7,8,10 find the median

Answer 1

Answer:

Median = 50

Step-by-step explanation:

We are given the following frequency distribution below;

    Classes               Frequency (f)                 Cumulative frequency (cf)

     20 - 30                        5                                              5

    30 - 40                         15                                            20

   40 - 50                       25                                            45

     50 - 60                       20                                            65

     60 - 70                        7                                              72

     70 - 80                        8                                              80

     80 - 90                       10                                            90

                                   ∑f = 90  

Firstly, we will calculate $\frac{N}{2}$, (where N = ∑f), $\frac{N}{2}$ = $\frac{90}{2}$ = 45.

So, the value of cumulative frequency just greater than or equal to 45 is 45.

Therefore, median class is 40 - 50 .

Now, Median formula =  $x_L + \frac{\frac{N}{2} -cf}{f_m}*c$ 

where, $x_L$ = lower limit of median class = 40

            N =  ∑f = 90   

           $f_m$ = frequency of median class = 25

            cf = cumulative frequency just above the median class = 20

             c = width of class interval = 10

So, Median = $40 + \frac{\frac{90}{2} -20}{25}*10$

                   = 40 + 10 = 50 .

Therefore, Median of given distribution is 50 .

Answer 2

Answer:

median is 50

Step-by-step explanation:

hope it helps u