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Finding the Fourth Proportional to 387.91, 580.60 and 285.17

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Solution

The fourth proportional to 387.91, 580.60 and 285.17 is: 426.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.91 : 580.60 = 285.17 : x
  2. Step 2: Convert to fraction form
    387.91/580.60 = 285.17/x
  3. Step 3: Cross multiply
    387.91x = 580.60 × 285.17
  4. Step 4: Simplify right side
    387.91x = 165,566.09
  5. Step 5: Solve for x
    x = 165,566.09/387.91
  6. Step 6: Final answer
    x = 426.82

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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.