The bar chart

The bar chart shows the results of the math test. How many percents of pupils achieved approximately better results than the class average?

Diagram: 1-10 pupils, 2-4 pupils, 3-6 pupils, 4-2 pupils, 5-4 pupils.
(lowest results are better)

Correct answer:

p =  53.8462 %

Step-by-step explanation:

$$\begin{gathered} n=10+4+6+2+4=26 \\ s=1\cdot 10+2\cdot 4+3\cdot 6+4\cdot 2+5\cdot 4=64 \\ a=\frac{s}{n}=\frac{64}{26}=\frac{32}{13}\doteq 2.4615 \\ p=100\cdot \frac{10+4}{n}=100\cdot \frac{10+4}{26}=53.8462\% \end{gathered}$$

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