Question

3-1 additional practice
leveled practice in 1–2, fill in the boxes to solve.

1. a school orchestra has 60 members. 20% of the members are percussionists. how many orchestra members are percussionists?

20% • 60 players
the number of percussionists is
\\(\frac{x}{60} \cdot \square = \frac{\square}{100} \cdot \square\\)
\\(x = \frac{\square}{100}\\)
\\(x = \square\\) percussionists

Explanation:

Step1: Set up proportion

We know that the percentage formula can be set up as a proportion. Let \( x \) be the number of percussionists. The proportion is \(\frac{x}{60}=\frac{20}{100}\). To solve for \( x \), we can cross - multiply. So the equation becomes \(\frac{x}{60}\cdot60=\frac{20}{100}\cdot60\).

Step2: Simplify the right - hand side

First, calculate the numerator of the right - hand side. We have \( 20\times60 = 1200 \). So the equation for \( x \) is \( x=\frac{20\times60}{100}\).

Step3: Calculate the value of \( x \)

Now, divide \( 1200 \) by \( 100 \). \( \frac{1200}{100}=12 \).

Answer:

In the proportion \(\frac{x}{60}\cdot\boldsymbol{60}=\frac{\boldsymbol{20}}{100}\cdot\boldsymbol{60}\), \(x = \frac{\boldsymbol{20\times60}}{100}\), and \(x=\boldsymbol{12}\) percussionists.