Question

the mean of a data X + 3 ,2 X + 6 is 15 then the value of x is​

Answer 1

Answer:

According to the question by using the formula we get, The value of x is 7.

Answer 2

Answer:

Given :-

The mean of the data x + 3, 2x + 6 is 15.

To Find :-

What is the value of x.

Formula Used :-

$\clubsuit♣ Mean Formula :</p><p>\begin{gathered}\mapsto \sf\boxed{\bold{\pink{Mean =\: \dfrac{Sum\: of\: Observations}{Total\: Number\: of\: Observations}}}}\\\end{gathered}↦Mean=TotalNumberofObservationsSumofObservations$

Solution :-

Given :

Mean = 15

Observations = x + 3, 2x + 6

According to the question by using the formula we get,

$\longrightarrow \sf 15 =\: \dfrac{x + 3 + 2x + 6}{2}⟶15=2x+3+2x+6$

$\longrightarrow \sf 15 =\: \dfrac{x + 2x + 3 + 6}{2}⟶15=2x+2x+3+6$

$\longrightarrow \sf 15 =\: \dfrac{3x + 3 + 6}{2}⟶15=23x+3+6$

$\longrightarrow \sf 15 =\: \dfrac{3x + 9}{2}⟶15=23x+9$

$\purple{\bigstar}\: \: \bf{By\: doing\: cross\: multiplication\: we\: get\: :-}★Bydoingcrossmultiplicationweget:−$

$\longrightarrow \sf 3x + 9 =\: 15(2)⟶3x+9=15(2)$

$\longrightarrow \sf 3x + 9 =\: 15 \times 2⟶3x+9=15×2$

$\longrightarrow \sf 3x + 9 =\: 30⟶3x+9=30$

$\longrightarrow \sf 3x =\: 30 - 9⟶3x=30−9$

$\longrightarrow \sf 3x =\: 21⟶3x=21$

$\longrightarrow \sf x =\: \dfrac{\cancel{21}}{\cancel{3}}⟶x=321$

$\longrightarrow \sf x =\: \dfrac{7}{1}⟶x=17$

$\longrightarrow \sf\bold{\red{x =\: 7}}⟶x=7$

$\therefore∴ The value of x is 7$