Question

Find the missing frequency in the following frequency distribution . if it is known that the mean of distribution = 50 . The total frequency is 120 ..

X = 10 , 30 , 50 , 70 , 90
F = 17 , F1 , 32 , F2 , 19

Answer 1

[0010001111]... Hello User... [1001010101]
Here's your answer...

X = 10 | 30 | 50 | 70 | 90
F = 17 | F1 | 32 | F2 | 19
XF = 170 | 30×F1 | 1600 | 70×F2 | 1710

Sum of F = 120
120 = 17+F1+32+F2+19
F1+F2 = 52

Sum of XF = 170+30F1+1600+70F2+1710
= 30F1 + 70F2 + 3480

Mean = (Sum of XF)÷(Sum of F)
50 = (30F1 + 70F2 + 3480)÷(120)
30F1 + 70F2 + 3480 = 6000
30F1 + 70F2 = 2520
3F1 + 7F2 = 252

Let F1 and F2 be x and y (makes it easier for me to type)

x+y = 52

3x+7y = 252
3x+3y = 156
-....-.........-
__________
4y = 96
y = 24
x + 24 = 52
x = 28

So F1 = 28 and F2 = 24

[0110100101]... More questions detected... [010110011110]
//Bot UnknownDude is moving on to more queries
//This is your friendly neighbourhood UnknownDude

Answer 2

Please see the attachment