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Finding the Fourth Proportional to 539.38, 809.21 and 478.90

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Solution

The fourth proportional to 539.38, 809.21 and 478.90 is: 718.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    539.38 : 809.21 = 478.90 : x
  2. Step 2: Convert to fraction form
    539.38/809.21 = 478.90/x
  3. Step 3: Cross multiply
    539.38x = 809.21 × 478.90
  4. Step 4: Simplify right side
    539.38x = 387,530.67
  5. Step 5: Solve for x
    x = 387,530.67/539.38
  6. Step 6: Final answer
    x = 718.47

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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.