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Finding the Fourth Proportional to 478.64, 717.60 and 387.20

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Solution

The fourth proportional to 478.64, 717.60 and 387.20 is: 580.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.64 : 717.60 = 387.20 : x
  2. Step 2: Convert to fraction form
    478.64/717.60 = 387.20/x
  3. Step 3: Cross multiply
    478.64x = 717.60 × 387.20
  4. Step 4: Simplify right side
    478.64x = 277,854.72
  5. Step 5: Solve for x
    x = 277,854.72/478.64
  6. Step 6: Final answer
    x = 580.51

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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.