Question

a) When a number x is added to the set of numbers 5, 7, 8, 12, 6, 10 and 11; the new mean is 9. Calculate the value of x?

Answer 1

Answer:

mean = sum of all observations ÷ number of observation

mean = (5+7+8+12+6+10+11+x) ÷8

9= (59+x)÷8

9*8=59+x

72=59+x.

72-59=x

x=13

Answer 2

Answer:

13

Step-by-step explanation:

5+7+8+12+6+10+11+x/8=9

59+x/8=9

59+x=72

x=72-59

=13