Question

Felix had a test average of 92.2 last semester. His first four test grades were 97, 94, 93, and 86. Use the formula =his score on the fifth test.

Answer 1

Given: The scores on Felix first four test as below

`97,94,93,86`

To Determine: The fifth score if the average score is 92.2

Solution

Giving the formula below

`\bar{x}=(x_1+x_2+...+x_n)/(n)`

From the given

`\begin{gathered} \bar{x}=92.2 \\ x_1=97;x_2=94 \\ x_3=93;x_4=86 \\ x_5=? \\ n=5 \end{gathered}`

Let us use the formula to get the fifth score as shown below

`\begin{gathered} (97+94+93+86+x_5)/(5)=92.2 \\ (370+x_5)/(5)=92.2 \\ 370+x_5=92.2*5 \\ 370+x_5=461 \\ x_5=461-370 \\ x_5=91 \end{gathered}`

Hence, the score on the fifth test is 91