Let the assumed mean (A) = 1650
Class interval |
Mid value (xi) |
di = xi - A = xi - 1650 |
ui = \(\frac{xi-1650}{100}\) |
Frequency (fi) |
fiui |
1400 - 1500 |
1450 |
-200 |
-2 |
3 |
-10 |
1500 - 1600 |
1550 |
-100 |
-1 |
10 |
-10 |
1600 - 1700 |
1650 |
0 |
0 |
20 |
0 |
1700 - 1800 |
1750 |
100 |
1 |
9 |
9 |
1800 - 1900 |
1850 |
200 |
2 |
6 |
12 |
1900 - 2000 |
1950 |
300 |
3 |
2 |
6 |
|
|
|
|
N = 52 |
\(\sum\)fiui =.7 |
We have,
A = 1650
h = 100
Mean = A + h \(\times\frac{\sum f_iu_i}{N}\)
\(=1650+100\times\frac{7}{52}\)
\(=1650 + \frac{1650}{13}\)
\(=\frac{21450+175}{13}=\frac{21625}{13}\)
\(=1663.46\)