Question

The following observations 40,42,45,x-1,x+1,51,54,62 are arranged in ascending order. If the mean is 49 , find the value of 'x'.
Hence, Find the mean of the above observation

Answer 1

The value of x is 49 and mean = 49

• Given observations 40, 42, 45, x-1, x+1, 51, 54, 62
• Number of observations = 8
• Mean of given data = 49
• We know that,

          Mean = (sum of observations)/(number of observations)

            49    = $\frac{40+42+45+x-1+x+1+51+54+62}{8}$

            49*8 = 294 + 2x

              2x = 392 - 294

               x = 49

Calculating mean:

• Missing observations are x-1 = 49-1 = 48, x+1 = 49+1 = 50
• Mean = (40+42+45+48+50+51+54+62)/8

                  = 392/8

                  = 49