Find the mean and standard deviation using short-cut method.
|
x i |
60 |
61 |
62 |
63 |
64 |
65 |
66 |
67 |
68 |
|
f i |
2 |
1 |
12 |
29 |
25 |
12 |
10 |
4 |
5 |
The data is obtained in tabular form as follows.
-
xi
fi
yi2
fiyi
fiyi2
60
2
–4
16
–8
32
61
1
–3
9
–3
9
62
12
–2
4
–24
48
63
29
–1
1
–29
29
64
25
0
0
0
0
65
12
1
1
12
12
66
10
2
4
20
40
67
4
3
9
12
36
68
5
4
16
20
80
100
220
0
286
Mean,
