Statistics - Online Test
Q1. In a group of students, mean weight of boys is 80 kg and mean weight of girls is 50kg.If the mean weight of all the students taken together is 60kg, then the ratio of the number of boys to that of the girls is
Answer : Option A
Explaination / Solution:
let the no. of boys be x and no. of girls be y
sum of weights of boys= 80x
sum of weights of girls = 50y
sum of weights of boys and girls together = 60(x + y)
hence, 80x + 50 y = 60x + 60y
which gives, 20x = 10 y
so, x:y = 1:2
Q2. For a normal distribution, we have
Answer : Option D
Explaination / Solution:
As in normal distribution, the curve is symmetric and unimodal. So, mean is at peak, mode is also at peak and median as well.
