Question
If the arithmetic mean of the data given below is 28, find (a) the missing frequency and (b) the median of the series.
|
Profit per retail shop (in Rs.) |
Number of retail shops |
|
0-10 10-20 20-30 30-40 40-50 50-60 |
12 18 27 – 17 6 |
Solution
|
Profit per retail shop (in Rs.) |
Mid-Value M |
Number of Retail Shops |
d |
d' |
fd' |
|
|
0-10 10-20 20-30 30-40 40-50 50-60 |
5 15 25 35 45 55 |
12 18 27 (X) suppose 17 6 |
-30 -20 -1 0 +1 +2 |
-3 -2 -1 0 +1 +2 |
-36 -36 -27 0 +17 +12 |
-99 +29 |
|
Σ f = X+80 |
Σ fd' = 70 |
Calculation of Median :
|
Profit of Retail Shops |
Frequency (f) |
cf |
|
0-10 10-20 20-30 30-40 40-50 50-60 |
12 18 27 20 17 6 |
12 20 57 77 94 100 |
|
Σ f= 100 |
