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Finding the Fourth Proportional to 639.67, 881.42 and 499.57

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Solution

The fourth proportional to 639.67, 881.42 and 499.57 is: 688.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.67 : 881.42 = 499.57 : x
  2. Step 2: Convert to fraction form
    639.67/881.42 = 499.57/x
  3. Step 3: Cross multiply
    639.67x = 881.42 × 499.57
  4. Step 4: Simplify right side
    639.67x = 440,328.49
  5. Step 5: Solve for x
    x = 440,328.49/639.67
  6. Step 6: Final answer
    x = 688.37

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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.