Question

If the arithmetic mean of the observations 30, 40, 50, x, 70 and 80 is 55 . Calculate the value of x:

• A. 65
• B. 60
• C. 55
• D. 50

Answer 1

Answer:

B. 60

arithmetic mean = total/number of observations 55 = ( 30+40+50+x+70+80)/6 55 = (270 + x)/6 330 = 270 + x x = 60