Answer: A) 20.9 ; B) 34years
Explanation:
Given the following :
AGE (X) - - - - - - - 19 - -20 - - - 21 - - - 22 - - - 23
FREQUENCY (F) - 2 - - 3 - - - - 1 - - - - 4 - - - - 1
A)
MEAN(X) = [AGE(X) × FREQUENCY (F)] ÷ SUM OF FREQUENCY
F*X = [(19 * 2) + (20 * 3) + ( 21 * 1)+(22 * 4)+(23 * 1)]
= 38 + 60 +21 + 88 + 23 = 230
SUM OF FREQUENCY = 2 + 3 + 1 + 4 + 1= 11
MEAN(X) = 230 / 11
X = 20.9
B)
WHEN A NEW PLAYER WAS ADDED :
MEAN (X) = 22
Let age of new player = y
Sum of Ages = 19 + 19 +20 + 20 + 20 + 21 + 22 + 22 + 22 + 22 + 23 + y
Number of players = 11 + 1 = 12
Mean(x) = sum of ages / number of players
New mean (x) = 22
x = (230 + y) / 12
22 = (230 + y) / 12
Cross multiply
264 = 230 + y
y = 264 - 230
y = 34 years