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The question asks for the ratio of the number of boys ("siswa") and girls ("siswi") based on the average test scores.

We are given:
- The average score of the boys is 5.
- The average score of the girls is 7.
- The overall average score in the class is 6.2.

Let the number of boys be \( x \) and the number of girls be \( y \).

The equation for the overall average score is given by:

\[
\frac{5x + 7y}{x + y} = 6.2
\]

Multiply both sides by \( x + y \):

\[
5x + 7y = 6.2(x + y)
\]

Expanding the right-hand side:

\[
5x + 7y = 6.2x + 6.2y
\]

Now, move all terms involving \( x \) to one side and all terms involving \( y \) to the other side:

\[
5x - 6.2x = 6.2y - 7y
\]

This simplifies to:

\[
-1.2x = -0.8y
\]

Dividing both sides by \(-0.8\):

\[
\frac{x}{y} = \frac{2}{3}
\]

So, the ratio of the number of boys to girls is \( 2:3 \).

Thus, the correct answer is **A) 2:3**.

Would you like any further explanation or have any questions?

Here are some related questions:
1. How do you calculate weighted averages in other scenarios?
2. What happens to the ratio if the class average changes?
3. How can you generalize this problem to more than two groups?
4. What role does the total number of students play in determining averages?
5. How would the result change if the boys and girls had the same average score?

**Tip**: When dealing with average problems, always try to break down the relationship into simple equations based on the data provided.

Nilai rata-rata tes matematika dari kelompok siswa dan kelompok siswi di suatu kelas berturut-turut adalah 5 dan 7. Jika nilai rata-rata di kelas tersebut adalah 6,2, maka perbandingan banyaknya siswa dan siswi adalah ....

Learn how to find the ratio of boys to girls in a class based on their average test scores. This problem uses weighted average concepts and algebra to determine that the ratio is 2:3, suitable for students in Grades 7-9.

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