Question

Help please. No spams. No copied answers. Chapter- Mean and median (for ungrouped data). Class 9 selina. MATHS​

Answer 1

Answer:

The value of x is 12.

Step-by-step explanation:

Let us first set up an equation.

9 + x + 14 + 18 + x + x + 8 + 10 + 4 / 9 = 11

3x + 63 / 9  = 11

Now, we will solve for x.

3x + 63 = 99

3x = 36

x = 12

Hope this helps!

Answer 2

$\huge\bold{\gray{\sf{Answer:}}}$

$\bold{Explanation:}$

$\sf\huge\underline{Question}$

Find x,if 9,x,14,18,x,x,8,10 and 4 have a mean of 11.

$\huge\bold{\gray{\sf{Answer:}}}$

$\bold{Explanation:}$

Formula for finding mean =>

$\sf Mean = \dfrac{Sum \: of \: all \: terms}{No.of \: terms}$

$\sf= > 11= \dfrac{9 + x + 14 + 18 +x + x + 8 + 10 + 4}{9}$

$\sf= > 11= \dfrac{22+14+18+9+3x}{9}$

$\sf= > 11= \dfrac{63+3x}{9}$

$\sf= > 63 + 3x = 99$

$\sf= > 3x = 99 - 63$

$\sf= > 3x = 36$

$\sf= > x = 12$

$\sf \therefore\:value\: of \:x\: is\: {\red{12}}$

Check

$\sf= > \dfrac{9 + 12 + 14 + 18 + 12 + 12 + 8 + 10 + 4}{9}$

$\sf= > \dfrac{99}{9} = 11$