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Finding the Fourth Proportional to 547.80, 820.55 and 431.70

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Solution

The fourth proportional to 547.80, 820.55 and 431.70 is: 646.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    547.80 : 820.55 = 431.70 : x
  2. Step 2: Convert to fraction form
    547.80/820.55 = 431.70/x
  3. Step 3: Cross multiply
    547.80x = 820.55 × 431.70
  4. Step 4: Simplify right side
    547.80x = 354,229.28
  5. Step 5: Solve for x
    x = 354,229.28/547.80
  6. Step 6: Final answer
    x = 646.64

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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.