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Finding the Fourth Proportional to 478.20, 660.78 and 361.56

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Solution

The fourth proportional to 478.20, 660.78 and 361.56 is: 499.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.20 : 660.78 = 361.56 : x
  2. Step 2: Convert to fraction form
    478.20/660.78 = 361.56/x
  3. Step 3: Cross multiply
    478.20x = 660.78 × 361.56
  4. Step 4: Simplify right side
    478.20x = 238,911.62
  5. Step 5: Solve for x
    x = 238,911.62/478.20
  6. Step 6: Final answer
    x = 499.61

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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.