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Finding the Fourth Proportional to 547.20, 820.80 and 392.80

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Solution

The fourth proportional to 547.20, 820.80 and 392.80 is: 589.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    547.20 : 820.80 = 392.80 : x
  2. Step 2: Convert to fraction form
    547.20/820.80 = 392.80/x
  3. Step 3: Cross multiply
    547.20x = 820.80 × 392.80
  4. Step 4: Simplify right side
    547.20x = 322,410.24
  5. Step 5: Solve for x
    x = 322,410.24/547.20
  6. Step 6: Final answer
    x = 589.20

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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.