Question

The average of 4 values is 20 and when a quantity is added to each value the average is 22. Find the quantity.​

Answer 1

Answer:

Unknown quantity is 4

Step-by-step explanation:

Let the quantity be x

So, sum of 4 values = 20*4=80

22=80+4x/4

22=4(20+x)/4

22=20+x

x=22-20

x=2

Therefore unknown quantity is 2

Answer 2

Answer:

The new quantity added to each value is 2.

Step-by-step explanation:

Average is defined as the ratio of summation of all the values to the number of values present in the list.

Average = (Sum of all the values)/(number of values present)

Step 1 of 2

According to the question,

The average of the 4 values is 20, i.e.,

Average = (sum of all the four values)/4

⇒ 20 = (sum of all the four values)/4

⇒ 20 × 4 = sum of all the four values

⇒ sum of all the four values = 80

Step 2 of 2

Let the quantity added to each value be $x$.

So, the quantity added to the all 4 values = $4x$

Then,

The new average of the four values is 22, i.e.,

Average = (sum of all the four values + $4x$)/4

⇒ 22 = (80 + $4x$)/4  (Since sum of all the four values = 80)

⇒ 22 × 4 = 80 + $4x$

⇒ 88 = 80 + $4x$

⇒ $4x$ = 88 - 80

⇒ $4x$ = 8

⇒ $x$ = 2

Therefore, the new quantity added to each value is 2.

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