
Chapter 4
160
Sl. no. Sales (in million rupees) Sales in ascending order
4 3,573.5 2,574.3
5 3,211.4 3,152.6
6 3,868.8 3,206.6
7 4,230.1 3,211.4
8 3,769.2 3,350.3
9 3,206.6 3,573.5
10 2,285.9 3,769.2
11 2,378 3,868.8
12 2,574.3 4,230.1
Q
1
is the size of
n +
⎛
⎝
⎜
⎞
⎠
⎟
1
4
th item = size of
12 1
4
+
⎛
⎝
⎜
⎞
⎠
⎟
th item = 3.25th value
Q
1
= 3rd value + 0.25(4th value – 3rd value) = 2378 + 0.25(2,574.3 – 2,378) = 2,378 + 49.07
= 2,427.07
Q
3
is the size of
3
1
4
n +
⎛
⎝
⎜
⎞
⎠
⎟
th item = size of 3
12 1
4
+
⎛
⎝
⎜
⎞
⎠
⎟
th item = 9.75th value
Q
3
= 9th value + 0.75(10th value – 9th value) = 3,573.5 + 0.75(3,769.2 – 3,573.5)
= 3,573.5 + 146.77 = 3,720.27
Hence, rst quartile Q
1
= 2,427.07 and ...