Question

if the mean of set of observations $\tt {X_1,X_1, ....,X_{10}}$ is 20 then mean of $\tt {X_1+4,X_2+8,X_3+12,....X_{10}+40}$​

Answer 1

$\huge \bf{ \red{ \mid{ \overline{ \underline{ANSWER}}} \mid}}$

$\tt\:required \: mean \: = \: \dfrac{1}{10} (x_1 + x_2 + ...x_{10}) + (4 + 8 + ... + 40)$

$\tt \dfrac{1}{10} (x_1 + .... + x_{10}) + \dfrac{4}{10} (1 + 2 + .... + 10)$

$\tt\:20 + \dfrac{4 \times 10 \times 11}{10 \times 2} \\ \\ = \: \: 42$

Answer 2

SOLUTION ✌

The mean of set of Observation.

___________________________

==) (x1+x2-------------x10)/10= Mean

==) (x1+x2-------------x10)/10= 20

==) (x1+x2----------------x10) = 20×10

==) (x1+x2----------------x10) = 200

THE SUM OF (x1+x2------x10) is 200

Now, equation is increasing by 4 , it means that the whole equation will increase by 220

then,

new mean = [( x1+x2------------x10) + 220]/10

==) (200+220)/10

==) 420/10

==) 42 mean answer.

HOPE IT HELP