Question

Find the mean of the 32 numbers, such that if the mean of 10 of them is 15 and the mean of 20 of them is 11. The last two numbers are 10.​

Answer 1

Given :-

◉ 32 number, from which the mean of 10 numbers is 15 and the mean of 20 of them is 11, The last two numbers are 10.

To Find :-

◉ Mean of those 32 numbers.

Solution :-

Given us the mean of 10 numbers, We know

⇒ Mean = Sum of Observations / Number of observations

⇒ 15 = x₁ / 10

⇒ x₁ = 150 ...(1)

Also,

⇒ Mean of 20 other numbers = Sum of observations / number of observations

⇒ 11 = x₂ / 20

⇒ x₂ = 220 ...(2)

Since, We are given the last two ( remaining numbers) as 10, So

⇒ Sum of observations = (1) + (2) + 10 + 10

⇒ Sum of observations = 150 + 220 + 20

⇒ Sum of observations = 390

Also, There are 32 numbers:

∴ Mean = Sum of observations / number of observations

⇒ Mean = 390 / 32

⇒ Mean = 12.1875

Hence, The mean of those 32 numbers is 12.1875

Answer 2

Answer:

answer is in attachment. please check it