Question

4. The mean of 20 numbers is 20. If 5 is added to each of the first ten numbers, what will be new mean of the new set of 20 numbers?​

Answer 1

Answer:

22.5

Step-by-step explanation:

Mean = sum/no.  *of observations

⇒ 20 = (sum of 20 no)/20

⇒ 400 = sum of 20 numbers

Then,

     5 is added to first ten numbers, it means 5 is added ten times.

  ⇒ Now the sum is increased by 5 * 10 = 50

∴ New sum = 400 + 50

                   = 450

  total numbers are still same(5 is added to the numbers & not particularly).

  Total numbers = 20

∴ Mean = 450/20 = 22.5

Answer 2

Answer:

$\large \dag$ Question :-

$\small\text{The mean of 20 numbers is 20 .If 5 is added to each of the first ten numbers .What will be new mean of the new set of 20 numbers.}$

$\large \dag$ Answer :-

$\small\text{The Answer to you question is The new mean of the new set of 20 numbers is 22.5}$

$\large \dag$ Solutions :-

Hey mate ,

$\small\text{In the question given that the mean of 20 numbers is 20.If 5 is added to the each of first ten numbers}$

$\small\text{Here we are going to find the new mean for the new set of 20 numbers.}$

$\small\text{After verifying your question we come to know that}$

$\small\text{Mean =Sum of numbers/no of observations}$

Here,

• Mean =20.
• Sum of numbers =20

By applying to it we get,

$\small\text{20=20[Sum of numbers]/20(no of observations)}$

$\small\text{20×20=20 (sum of numbers)}$

$\small\text{400 =20 (sum of numbers)}$

$\small\text{In the question given that 5 is added to the each of first ten number}$

Now,

• $\small\text{The sum totally increased by =5×10=50}$

Now,

• $\small\text{The new sum =400+50=450}$

But ,

• $\small\text{Here we know that total numbers =20}$

$\small\text{According to this we should divide new sum by the total number}$

• $\small\text{450/20=22.5}$

Hence,

• $\small\text{Mean =22.5.}$

$\large \dag$ Hope it helps u mate .