Question

The A.M. of a 50 set of numbers is 38. If two numbers of the set, namely 55 and 45 are discarded, the A.M. of the remaining set of numbers is

• A. 38.5
• B. 37.5
• C. 36.5
• D. 36

Answer 1

Answer: (B)

37.5

Answer 2

Given, $\frac{\Sigma x_{i}}{50} = 38,\therefore\Sigma x_{i} = 1900$

New value of $\Sigma x_{i} = 1900 - 55 - 45 = 1800$, $n = 48$

∴ New mean $= \frac{1800}{48} = 37.5$.