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Finding the Fourth Proportional to 387.72, 580.62 and 319.68

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Solution

The fourth proportional to 387.72, 580.62 and 319.68 is: 478.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.72 : 580.62 = 319.68 : x
  2. Step 2: Convert to fraction form
    387.72/580.62 = 319.68/x
  3. Step 3: Cross multiply
    387.72x = 580.62 × 319.68
  4. Step 4: Simplify right side
    387.72x = 185,612.60
  5. Step 5: Solve for x
    x = 185,612.60/387.72
  6. Step 6: Final answer
    x = 478.73

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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.