Problema Solution

Average of 12 observation is 37. Of average of 4 observation is 29 and average of next 5 is 41,10th observation is 2 more than 11th and 11th observation is 26 more than the 12th observation.find 12 observation?

Answer provided by our tutors

if average of the 4 observation is 29 then the sum of 4 observations is: 4*29


if average of the next 5 is 41 then the sum of this 5 observations is: 5*41


x = the 12th observation


x + 26 = the 11th observation


x + 26 + 2 = the 10th observation


using that the average of 12 observation is 37 we can write:


(4*29 + 5*41 + x + x + 26 + x + 26 + 2)/12 = 37


by solving we find:


x = 23


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the 12th observation is 23.