Question

A teacher is teaching two statistics classes on the final exam the 20 students in the first class had a mean score of 74 while the 25 students in the second class had a mean of 56 if the teacher combined the classes together what will the average final exam score be of the two classes together

Answer 1

Let us write the formula for mean,

$\text{Mean=}\frac{\text{Sum of outcomes}}{\text{ number of outcomes}}$

For the first class which consists of 20 students, the sum of their scores will be calculated by,

$\begin{gathered} 74=\text{ }\frac{\text{sum of scores for the first class}}{20} \\ \text{ Sum of scores for the first class = 74}\times20 \\ \text{ Sum of scores for the first class}=1480 \end{gathered}$

For the second class which consists of 25 students, the sum of their scores will be calculated by,

$\begin{gathered} 56=\frac{\text{sum of scores for the second class}}{25} \\ \text{Sum of scores for the second class}=56\times25 \\ \text{Sum of scores for the second class}=1400 \end{gathered}$

Therefore, for the combined classes the average final exam score will be,

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