Question

46. The average weight of 20 students is 84 kg. If the weight of the teacher be
included the average increases by 3 kg. Find the weight of the teacher.
(a) 147 Kg. (b) 150 Kg. (c) 135 Kg. (d) 128 ​

Answer 1

Answer:

Mean = sum/total no. of observations

84 = sum/20

sum = 84 × 20 = 1680

Let the weight of teacher be x

Mean = 84 + 3 = 87

Total people = 21

87 = (sum + x) / 21

87 × 21 = sum + x

1827 = sum + x

x = 1827 - sum

x = 1827 - 1680

x = 147

Weight of the teacher is 147 kg

Hope it helps.....