Question

plz tell me as soon as possible

Answer 1

C.I. ___Freq.__X__fx
0-20____17__10___170
20-40___f1__30____30f1
40-60___32_50__1600
60-80___f2__70___70f2
80-100__19__90__1710

Sum:___120___3480+30f1+70f2

68+f1+f2=120
f1+f2=120-68
f2=52-f1

50=3480+30f1+70f2 / 120
50=10(348+3f1+7f2) / 120
50=348+3f1+7f2 / 12
50 × 12 = 348 + 3f1 + 7f2
600-348 = 3f1 + 52 - f1
252 -52= 2f1
200/2=f1
f1 = 100

f2=52-f1
=52-100= -48

Hope it helps you! :)