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Finding the Fourth Proportional to 820.62, 1,229.90 and 560.20

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Solution

The fourth proportional to 820.62, 1,229.90 and 560.20 is: 839.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.62 : 1,229.90 = 560.20 : x
  2. Step 2: Convert to fraction form
    820.62/1,229.90 = 560.20/x
  3. Step 3: Cross multiply
    820.62x = 1,229.90 × 560.20
  4. Step 4: Simplify right side
    820.62x = 688,989.98
  5. Step 5: Solve for x
    x = 688,989.98/820.62
  6. Step 6: Final answer
    x = 839.60

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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.