Given: The scores on Felix first four test as below
[tex]97,94,93,86[/tex]
To Determine: The fifth score if the average score is 92.2
Solution
Giving the formula below
[tex]\bar{x}=\frac{x_1+x_2+...+x_n}{n}[/tex]
From the given
[tex]\begin{gathered} \bar{x}=92.2 \\ x_1=97;x_2=94 \\ x_3=93;x_4=86 \\ x_5=? \\ n=5 \end{gathered}[/tex]
Let us use the formula to get the fifth score as shown below
[tex]\begin{gathered} \frac{97+94+93+86+x_5}{5}=92.2 \\ \frac{370+x_5}{5}=92.2 \\ 370+x_5=92.2\times5 \\ 370+x_5=461 \\ x_5=461-370 \\ x_5=91 \end{gathered}[/tex]
Hence, the score on the fifth test is 91
