Question

The mean of first three observations is 15 and the mean of next two
observation is 20. The mean of all five observations is -​

Answer 1

Answer:

I think the answer will be 88

Answer 2

The mean of all five observations is 17.

Step-by-step explanation:

Let the five observations are a, b, c, d and e.

The mean of first three observations is 15.

=> $\frac{a+b+c}{3} = 15$

=> a + b + c = 15 x 3 = 45................(i)

Let the mean of next two observations is 20.

=> $\frac{d+e}{2} = 20$

=> d + e = 20 x 2 = 40..............(ii)

The mean of all five observations,

= $\frac{a+b+c+d+e}{5}$

= $\frac{45+40}{5}$       [By using equation(i) and (ii)]

= $\frac{85}{5}$

= 17

Hence, the mean of all five observations is 17.