Median simple

7 Median

The following section describes the procedurę to be foliowe d, using the data of Table 1.

5. Procedurę for calculating the median

To całculate the median for a simple (discrete) freąuency distribution, the following procedurę should be followed.

STEP 4 The median is the x-value corresponding to the F value identified in STEP 3

Notę: Sometimes X/*is replaced by N for convenience.

6. Example 2 (The median for a simple discrete freęuency distribution.)

Question

Całculate the median for the following distribution of delivery times of orders sent out from a firm.

r Delivery time (days)	0 1 2 3 4 5 6 7 8 9 10 11
Number of orders V__	4 8 11 12 21 15 10 4 2 2 1 1 J

Answer

Delivery time (days) (x)	Number of orders (0	Cum (F)
0	4	4
1	8	12
2	11	23
3	12	35
9	21 15	pó] 71
6	10	81
7	4	85
8	2	87
9	2	89
10	1	90
11	1	91

STĘPI

N+1    qo

The median is the -—- th =—th = 46th item 2    2

STEP 2

The F column is shown in the accompanying table

STEP 3

The first F value to exceed 46 is F=56 STEP 4

The median is thus 4 (days)

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