array |c|c|c|c|c|c| Class & 0-20 & 20-40 & 40-60 & 60-80 & 80-100 Frequency & 17 & p+q & 32 & p-3 q & 19 array The total frequency is 120 . The mean is 50 . If the frequency of each class is doubled, then what would be the mean?

Step-by-step solution

array |c|c|c|c| C.I & f _ i & x _ i & f _ i X _ i 0-20 & 17 & 10 & 170 20-40 & P + q & 30 & 30( P +8) 40-60 & 32 & 50 & 1600 60-80 & P -3 q & 70 & 70 P -210 q 80-100 & 19 & 90 & 1710 array 68+2 P-2 q 3480+100 p-180 q 68+2 P-2 q=120 p - q =26 ...(i) aligned & 50= 3480+100 P-180 q 120 & 6000=3480+100 P-180 q aligned 5 P-9 q=126 ...(ii) On solving equation (i) and (ii) we get P =27 and q =1 If frequency of each class is doubled aligned & New Mean = _ i =1 ^ n x _ i 2 fi 2 fi =2 _ i =1 ^ n x _ i fi 2 fi & = _ i =1 ^ n