Question

What is the arithmetic mean in the following table on the variable score?

Student_ID	Score
$R304110$	$0.98$
$R304003$	$0.88$
$R102234$	$0.65$
$R209939$	$0.92$

• A. $0.92$
• B. $0.88$
• C. $0.765$
• D. $0.8575$

Answer 1

The correct option is D

$0.8575$

Explanation for the correct option:

The formula of mean is $\mathrm{Mean}=\frac{\mathrm{Sum}\mathrm{of}\mathrm{all}\mathrm{values}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{values}}$.

The number of values is given as $4$.

Add $0.98,0.88,0.65,0.92$ to obtain the sum of the values.

$$\begin{gathered} \mathrm{Sum}=0.98+0.88+0.65+0.92 \\ \therefore \mathrm{Sum}=3.43 \end{gathered}$$

Substitute $3.43$ for the sum of all values and $4$ for the total number of values in the equation $\mathrm{Mean}=\frac{\mathrm{Sum}\mathrm{of}\mathrm{all}\mathrm{values}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{values}}$.

$$\begin{gathered} \mathrm{Mean}=\frac{3.43}{4} \\ \therefore \mathrm{Mean}=0.8575 \end{gathered}$$

Hence, option (D) is correct.