Question

The mean of five observations is 17. If one more observation is included, then mean of the new data is 18. Find the observation which is included

Answer 1

Answer:

The new value that was included was 23.

Step-by-step explanation:

Mean = Sum of the observations/ No. of observations

In the above question;

Let x be the total sum of the 5 observations

Hence, 17 = x/5

The sum of the observations, x = 17 x 5 = 85

Let the number which is included be y. Thus, the no. of observations increases to 6

The sum of the earlier observations, i.e., x and the new value y yields a mean of 18

Thus,  

(x+y)/ 6 = 18

As shown above; x = 85

Thus,

85 + y = 18 x 6

85 + y = 108

Finally; y = 23

The new number that was included is 23