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Finding the Fourth Proportional to 637.20, 878.40 and 403.92

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Solution

The fourth proportional to 637.20, 878.40 and 403.92 is: 556.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    637.20 : 878.40 = 403.92 : x
  2. Step 2: Convert to fraction form
    637.20/878.40 = 403.92/x
  3. Step 3: Cross multiply
    637.20x = 878.40 × 403.92
  4. Step 4: Simplify right side
    637.20x = 354,803.33
  5. Step 5: Solve for x
    x = 354,803.33/637.20
  6. Step 6: Final answer
    x = 556.82

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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.