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Finding the Fourth Proportional to 420.53, 579.92 and 280.65

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Solution

The fourth proportional to 420.53, 579.92 and 280.65 is: 387.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.53 : 579.92 = 280.65 : x
  2. Step 2: Convert to fraction form
    420.53/579.92 = 280.65/x
  3. Step 3: Cross multiply
    420.53x = 579.92 × 280.65
  4. Step 4: Simplify right side
    420.53x = 162,753.14
  5. Step 5: Solve for x
    x = 162,753.14/420.53
  6. Step 6: Final answer
    x = 387.02

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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.