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Finding the Fourth Proportional to 420.32, 580.24 and 280.66

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Solution

The fourth proportional to 420.32, 580.24 and 280.66 is: 387.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.32 : 580.24 = 280.66 : x
  2. Step 2: Convert to fraction form
    420.32/580.24 = 280.66/x
  3. Step 3: Cross multiply
    420.32x = 580.24 × 280.66
  4. Step 4: Simplify right side
    420.32x = 162,850.16
  5. Step 5: Solve for x
    x = 162,850.16/420.32
  6. Step 6: Final answer
    x = 387.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.