Question

If the arthimetic mean of 5,7,9x is 9 the value of x is

Answer 1

Answer:

Arithemtic mean is as same as mean or average.

It is given by the ratio of sum of observations to number of observations

Here,

Sum of observations = 5 + 7 + 9x

Sum of observations = 12 + 9x

Number of observations = 3

Mean = 9

= > 9 = ( 12 + 9x ) / 3

= > 9 = 3( 4 + 3x ) / 3

= > 9 = 4 + 3x

= > 9 - 4 = 3x

= > 5 = 3x

= > 5/3 = x

Answer 2

Answer :

Given -

• Arithmetic mean = 9
• The numbers are 5, 7 and 9x

To Find -

• Value of x ?

Solution -

We know that, Arithmetic mean = Sum of numbers/Tital numebers.

So, Arithmetic mean = (a + b + c)/3.

Hence,

⇒ (5 + 7 + 9x)/3 = 9

⇒ 12 + 9x = 9 × 3

⇒ 12 + 9x = 27

⇒ 9x = 27 - 12

⇒ 9x = 15

⇒ x = 15/9

⇒ x = 5/3

Hence, The value of x is 5/3.