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Finding the Fourth Proportional to 402.40, 552.68 and 392.80

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Solution

The fourth proportional to 402.40, 552.68 and 392.80 is: 539.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.40 : 552.68 = 392.80 : x
  2. Step 2: Convert to fraction form
    402.40/552.68 = 392.80/x
  3. Step 3: Cross multiply
    402.40x = 552.68 × 392.80
  4. Step 4: Simplify right side
    402.40x = 217,092.70
  5. Step 5: Solve for x
    x = 217,092.70/402.40
  6. Step 6: Final answer
    x = 539.49

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.