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Finding the Fourth Proportional to 387.78, 580.41 and 285.04

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Solution

The fourth proportional to 387.78, 580.41 and 285.04 is: 426.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.78 : 580.41 = 285.04 : x
  2. Step 2: Convert to fraction form
    387.78/580.41 = 285.04/x
  3. Step 3: Cross multiply
    387.78x = 580.41 × 285.04
  4. Step 4: Simplify right side
    387.78x = 165,440.07
  5. Step 5: Solve for x
    x = 165,440.07/387.78
  6. Step 6: Final answer
    x = 426.63

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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.