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Work Shown:
We have this set of data
[tex]\begin{tabular}{|l|l|}\textbf{game} & \textbf{goals}\\ 1 & 5 \\ 2 & 6 \\ 3 & 6\\ 4 & x \end{tabular}[/tex]
where x is some positive whole number. Add up everything in the second column:
5+6+6+x = x+17
This represents the total number of goals made over the four games.
Divide this over the number of games played (4) and set that equal to the mean of 6. Solve for x.
(x+17)/4 = 6
x+17 = 4*6
x+17 = 24
x = 24-17
x = 7
7 goals were scored in the fourth game.