Question

The frequency of three numbers 12 , 15 , 17 are x+2 , x , x-1 . If the mean of this data is 13.9 then find the value of x .
If you want to be the brainliest then give me a write ans .​

Answer 1

Answer:

3

Step-by-step explanation:

x₁ = 12 , f₁ = x+2

x₂ = 15 , f₂ = x

x₃ = 17 , f₃ = x-1

∴Mean = (x₁f₁ + x₂f₂ + x₃f₃+......xₙfₙ) / (f₁ + f₂+f₃+........fₙ)

⇒ 13.9 = 12( x+2) + 15x + 17(x-1) / (x + 2 + x + x - 1)

⇒ 13.9*(3x + 1) = 12x + 24 + 15x + 17x - 17

⇒ 44x + 7 = 41.7x + 13.9

⇒ 2.3x = 6.9

∴ x = 6.9/2.3 = 3