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Finding the Fourth Proportional to 402.60, 604.80 and 391.80

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Solution

The fourth proportional to 402.60, 604.80 and 391.80 is: 588.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.60 : 604.80 = 391.80 : x
  2. Step 2: Convert to fraction form
    402.60/604.80 = 391.80/x
  3. Step 3: Cross multiply
    402.60x = 604.80 × 391.80
  4. Step 4: Simplify right side
    402.60x = 236,960.64
  5. Step 5: Solve for x
    x = 236,960.64/402.60
  6. Step 6: Final answer
    x = 588.58

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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.