What will be the mean and range of their ages in 5 years time?

Question

The mean and range of their ages is 17 and 26. There are 4 in the family

Answer 1

Logically the mean will increase by 5 since we add 5 a total of 4 times and then divide by 4.

New mean age should be 22.

 

Look at the mean, which is the arithmetic average:

 

AgeSum/4 = 17

AgeSum = 68

Originally the 4 ages added to 68

 

To this we will add 20 years because we add 5 years to each of 4 numbers:

New sum of the ages is 88

88/4 = 22

New mean age 22 years

 

By a range of 26 I assume you mean the difference in age between the

youngest and oldest is 26 years.  This will remain the same since each

increased by the same amount.  Range remains 26