Question

The mean of the observations
A, A + 1, 2A + 3,3A + 1 and A-1
is 12 find the value of A.
Your answer​

Answer 1

Step-by-step explanation:

$mean = \frac{sum \: of \: the \: observations}{total \: number \: of \: observation}$

$12 = \frac{a + a + 1 + 2a + 3 + 3a + 1 + a - 1}{5}$

$60 = 8a + 4$

$8a = 60 - 4 = 56$

$a = \frac{56}{8} = 7$

Answer 2

Given:

• Observation :- A, A+1, 2A + 3, 3A + 1 and A-1
• Mean = 12

Find:

• Value of A will be ?

Solution:

we, know that

$\underline{\boxed{\sf\to Mean = \dfrac{sum \: of \: all \: terms}{no. \: of \: terms}}}$

Where,

• Sum of all terms = A + A+1 + 2A + 3 + 3A + 1 + A-1
• No. if terms = 5
• Mean = 12

So,

$\sf\to Mean = \dfrac{sum \: of \: all \: terms}{no. \: of \: terms}$

$\sf :\implies 12= \dfrac{A + A+1 + 2A + 3 + 3A + 1 + A-1}{5}$

$\sf :\implies 12= \dfrac{8A + 4}{5}$

$\sf :\implies 12 \times 5= 8A +4$

$\sf :\implies 60= 8A +4$

$\sf :\implies 60 - 4= 8A$

$\sf :\implies 56= 8A$

$\sf :\implies A = \dfrac{56}{8} = 7$

$\sf \therefore A = 7$

Hence, the value of A will be 7