Question

The table shows the ages of players on a football team.

Age
Frequency
a) Work out the mean age of the team.
Round your answer to 1 decimal place.
19
2.
20
3
21
1
b) A new player joins the team and raises
the mean age to 22.
22
4
23
1
Work out the age of this new player.

Answer 1

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