Question

Find the mean of 30 number if it is given that mean of ten of then is 12 and the mean of remaining 20 is 9.

Answer 1

Answer:

10

Step-by-step explanation:

Mean of 10 no. = 12

let the sum of 10 no be X

X/10 = 12

X = 120

Mean of 20 = 9

let the sum of no be y

y/ 20 = 9

y = 180

sum of 30 no. = s(10) + s(20)

= 180 + 120

= 300

mean of 30 n = sum(30)/30

= 300/30

= 10