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Finding the Fourth Proportional to 478.78, 660.42 and 354.40

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Solution

The fourth proportional to 478.78, 660.42 and 354.40 is: 488.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.78 : 660.42 = 354.40 : x
  2. Step 2: Convert to fraction form
    478.78/660.42 = 354.40/x
  3. Step 3: Cross multiply
    478.78x = 660.42 × 354.40
  4. Step 4: Simplify right side
    478.78x = 234,052.85
  5. Step 5: Solve for x
    x = 234,052.85/478.78
  6. Step 6: Final answer
    x = 488.85

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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.