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Finding the Fourth Proportional to 523.70, 785.90 and 280.40

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Solution

The fourth proportional to 523.70, 785.90 and 280.40 is: 420.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    523.70 : 785.90 = 280.40 : x
  2. Step 2: Convert to fraction form
    523.70/785.90 = 280.40/x
  3. Step 3: Cross multiply
    523.70x = 785.90 × 280.40
  4. Step 4: Simplify right side
    523.70x = 220,363.13
  5. Step 5: Solve for x
    x = 220,363.13/523.70
  6. Step 6: Final answer
    x = 420.78

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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.