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Finding the Fourth Proportional to 639.92, 881.76 and 499.82

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Solution

The fourth proportional to 639.92, 881.76 and 499.82 is: 688.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.92 : 881.76 = 499.82 : x
  2. Step 2: Convert to fraction form
    639.92/881.76 = 499.82/x
  3. Step 3: Cross multiply
    639.92x = 881.76 × 499.82
  4. Step 4: Simplify right side
    639.92x = 440,721.28
  5. Step 5: Solve for x
    x = 440,721.28/639.92
  6. Step 6: Final answer
    x = 688.71

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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.