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Finding the Fourth Proportional to 639.59, 882.76 and 391.06

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Solution

The fourth proportional to 639.59, 882.76 and 391.06 is: 539.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.59 : 882.76 = 391.06 : x
  2. Step 2: Convert to fraction form
    639.59/882.76 = 391.06/x
  3. Step 3: Cross multiply
    639.59x = 882.76 × 391.06
  4. Step 4: Simplify right side
    639.59x = 345,208.94
  5. Step 5: Solve for x
    x = 345,208.94/639.59
  6. Step 6: Final answer
    x = 539.73

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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.