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Finding the Fourth Proportional to 387.20, 543.70 and 387.20

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Solution

The fourth proportional to 387.20, 543.70 and 387.20 is: 543.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.20 : 543.70 = 387.20 : x
  2. Step 2: Convert to fraction form
    387.20/543.70 = 387.20/x
  3. Step 3: Cross multiply
    387.20x = 543.70 × 387.20
  4. Step 4: Simplify right side
    387.20x = 210,520.64
  5. Step 5: Solve for x
    x = 210,520.64/387.20
  6. Step 6: Final answer
    x = 543.70

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.