Question

8. The mean of 25 observations is 80, and the mean of 55 ob
-rations is 65. Find the mean of the whole data.​

Answer 1

$\huge\pink{\boxed{\blue{\boxed{ \purple{ \boxed{{\pink{Answer}}}}}}}} \\ \large\pink{\boxed{\blue{\boxed{ \purple{ \boxed{{\pink{Your~answer↓}}}}}}}}$

Given :-

Number of observations, n1 = 25

Mean of 25 observations, x1 = 80

Number of observations, n2 = 55

Mean of 55 observations, x2 = 65

To find :-

Combined mean of 80 observations.

Formula used :-

$Combined \: mean, \: X = \frac{n1x1 + n2x2}{n1 + n2}$

Solution :-

n1 = 25

n2 = 55

x1 = 80

x2 = 65

$Combined \: mean, of \: 80 \: observations \\ \: X = \frac{n1x1 + n2x2}{n1 + n2} \\ X = \frac{25 \times 80 + 55 \times 65}{25 + 55} \\ X = \frac{2000 + 1375}{80} \\ X = \frac{3375}{80} \\ X = 42.1875$

$\huge \fcolorbox{black}{cyan}{♛Hope it helps U♛}$

Answer 2

Answer:

x = 42.1875 is the answer........