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Finding the Fourth Proportional to 509.60, 763.80 and 381.20

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Solution

The fourth proportional to 509.60, 763.80 and 381.20 is: 571.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.60 : 763.80 = 381.20 : x
  2. Step 2: Convert to fraction form
    509.60/763.80 = 381.20/x
  3. Step 3: Cross multiply
    509.60x = 763.80 × 381.20
  4. Step 4: Simplify right side
    509.60x = 291,160.56
  5. Step 5: Solve for x
    x = 291,160.56/509.60
  6. Step 6: Final answer
    x = 571.35

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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.