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Finding the Fourth Proportional to 420.38, 580.02 and 280.58

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Solution

The fourth proportional to 420.38, 580.02 and 280.58 is: 387.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.38 : 580.02 = 280.58 : x
  2. Step 2: Convert to fraction form
    420.38/580.02 = 280.58/x
  3. Step 3: Cross multiply
    420.38x = 580.02 × 280.58
  4. Step 4: Simplify right side
    420.38x = 162,742.01
  5. Step 5: Solve for x
    x = 162,742.01/420.38
  6. Step 6: Final answer
    x = 387.13

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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.