Question

Please answer this question
Q.24) Find the missing frequencies f1, f2 and f3 in the following frequency distribution, when it is given that f2 : f3 = 4 : 3 and mean = 50

Answer 1

Answer: 17+f1+f2+f3+19= 120

F1+f2+f3=120-36=84... eqn 1

It is given that f2:f3=4:3

Therfore 3f2-4f3=0.... eqn 2

Mean=50 (given)

Mean= fixi/n

50= 170+30f1+50f2+70f3+1710/120

412=3f1+5f2+7f3.... eqn 3

Solving the eqns

F1=84-f2-f3

3f1=412-5f2-7f3

On solving.. 160=2f2+4f3

But 4f3=3f2..fromeqn 2

160=5f2

F2=160/5=32

3f2-4f3=0

3×32-4f3=0

96=4f3

F3=24

F1+f2+f3=84

F1=84-56

F1=28

Step-by-step explanation: