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Finding the Fourth Proportional to 487.61, 729.68 and 390.73

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Solution

The fourth proportional to 487.61, 729.68 and 390.73 is: 584.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.61 : 729.68 = 390.73 : x
  2. Step 2: Convert to fraction form
    487.61/729.68 = 390.73/x
  3. Step 3: Cross multiply
    487.61x = 729.68 × 390.73
  4. Step 4: Simplify right side
    487.61x = 285,106.82
  5. Step 5: Solve for x
    x = 285,106.82/487.61
  6. Step 6: Final answer
    x = 584.70

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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.