Question

5. The weights of tea in 70 packets are shown in the following table. 200-201 Weight (in gm) 201 - 202 202 - 203 203 - 204 204 - 205 - 205 - 206 No. of packets 6 10 16 15 24 8 Find the mean weight of packets using assumed mean method.​

Answer 1

Step-by-step explanation:

Let us choose a = 201.5, h = 1, then di = xi - 201.5 and

ui = (xi−201.5)/1

Using Step-deviation method, the given data is shown as follows:

Weight (in grams) Number of packets (fi) Class mark (xi) di = xi - 201.5 ui = (xi−201.5)/1 fiui

200 - 201 13 200.5 1 1 13

201 - 202 27 201.5 0 0 0

202 - 203 18 202.5 -1 -1 -18

203 - 204 10 203.5 -2 -2 -10

204 - 205 1 204.5 -3 -3 -3

205 - 206 1 205.5 -4 -4 -4

Total ∑fi=70 ∑(fi×ui)=-22

∑FiUi =22

H=1

N=70

a=201.5

Mean = a+∑FiUi ×h

n

= 201.5 + - 22 × 1

70

= 201.5 – 0.31

= 201.19