Question

The mean of the following data is 50 find missing frequency X- 10, 30, 50, 70, 90, total F- 17, F1, 32, F2, 19,120

Answer 1

f1 + f2= 120-(17+32+19)
f1+f2= 120-68
f1=52-f2--------(1)
mean=sigma xi fi/ sigma fi
50= 3480+30F1+70F2/ 120
50= 10(348+3F1+7F2)/120
600=348+3F1+7F2
Sub equation 1 
600-348= 3(52-f2)+7f2
252= 156-3f2+7f2
96=4f2
f2=24
therefore,
f1=52-24=28

Answer 2

Answer:

Step-by-step explanation:

f1 + f2= 120-(17+32+19)

f1+f2= 120-68

f1=52-f2--------(1)

mean=sigma xi fi/ sigma fi

50= 3480+30F1+70F2/ 120

50= 10(348+3F1+7F2)/120

600=348+3F1+7F2

Sub equation 1  

600-348= 3(52-f2)+7f2

252= 156-3f2+7f2

96=4f2

f2=24

therefore,

f1=52-24=28