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Finding the Fourth Proportional to 509.72, 764.62 and 221.18

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Solution

The fourth proportional to 509.72, 764.62 and 221.18 is: 331.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.72 : 764.62 = 221.18 : x
  2. Step 2: Convert to fraction form
    509.72/764.62 = 221.18/x
  3. Step 3: Cross multiply
    509.72x = 764.62 × 221.18
  4. Step 4: Simplify right side
    509.72x = 169,118.65
  5. Step 5: Solve for x
    x = 169,118.65/509.72
  6. Step 6: Final answer
    x = 331.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.