Question

If the mean of the data x+3, 2x+6 is 15, then the value of x is
a.3
b.0
c.7
d.9​

Answer 1

Step-by-step explanation:

Given mean of 7,9,x+3,12,2x−1,3 is 9

i.e.,

6

7+9+x+3+12+2x−1+3

=9

⇒3x+33=54

⇒3x=21

⇒x=

3

21

=7

∴ value of x=7

Answer 2

$\huge \mathtt \purple{Solution}$

$\huge\gray{\mid{\underline{\overline{\textbf{Given}}}\mid}}$$\huge\gray{\mid{\underline{\overline{\textbf{data=x+3,2x+6 }}}\mid}}$

$\huge\red{\mid{\underline{\overline{\textbf{Mean }}}\mid}}$$\huge\red{\mid{\underline{\overline{\textbf{ of}}}\mid}}$$\huge\red{\mid{\underline{\overline{\textbf{the }}}\mid}}$$\huge\red{\mid{\underline{\overline{\textbf{data }}}\mid}}$$\huge\red{\mid{\underline{\overline{\textbf{is 15 }}}\mid}}$

$\huge\blue{\mid{\fbox{\tt{*NOTE*}}\mid}}$

☆Mean is the average of the values in the data set .

Therefore,

⠀⠀⠀⠀⠀

Mean =x+3+(2x+6)

⠀⠀⠀⠀⠀⠀⠀2

⠀A.T.P

⟹(3x+9)/2= 15

⟹3x+9= 15×2

⟹3x+9=30

⟹3x= 30-9

⟹x= 21/3

⟹x=7

$\huge{\pink{\boxed{\pink{\underline{\gray{\mathscr{x=7}}}}}}}$