1.7 Summation symbol

The following table lists four pairs of m and fvalues:

12

f 5

m

15

9

20

10

30

16/nCompute the following:

(a) Σm (b) ΣfΖ (c) Σmf (d) Σmef

m

12

15

20

30

Σ m = 77

f

5

9

10

16

fr

25

81

100

256

mof

60

135

200

480

Σ f = 40 Ef = 462 Σm· f = 875

me. f

(12)(12)(5)=720

(15)(15)(9) = 2025

(20)(20)(10) 4000

(30)(30)(16)=14400

Σ21,145