Class interval (exclusive) |
Class interval (inclusive) |
Frequency |
Cumulative frequency |
55 - 64 |
54.5 - 64.5 |
1 |
1 |
65 - 74 |
64.5 - 74.5 |
2 |
3 |
75 - 84 |
74.5 - 84.5 |
9 |
12 |
85 - 94 |
84.5 - 94.5 |
22 |
34 (F) |
95 - 104 |
94.5 - 104.5 |
33 (f) |
37 |
105 - 114 |
104.5 - 114.5 |
22 |
89 |
115 - 124 |
114.5 - 114.5 |
8 |
97 |
125 - 134 |
114.5 - 124.5 |
2 |
99 |
135 - 144 |
134.5 - 144.5 |
1 |
100 |
|
|
N = 100 |
|
We have,
N = 100
\(\frac{N}{2}=\frac{100}{2}=50\)
The cumulative frequency just greater than \(\frac{N}{2}\) s 67 then the median class 94.5-104.5 such that,
l = 94.5, f = 33, F = 34, h = 104.5 – 94.5 = 10
Median = I + \(\frac{\frac{N}{2}-F}{f}\times h\)
\(=94.5+\frac{50-34}{33}\times10\)
\(=94.5+\frac{16}{33}\times10\)
\(=94.5+4.85=99.35\)