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Finding the Fourth Proportional to 639.96, 882.98 and 391.19

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Solution

The fourth proportional to 639.96, 882.98 and 391.19 is: 539.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.96 : 882.98 = 391.19 : x
  2. Step 2: Convert to fraction form
    639.96/882.98 = 391.19/x
  3. Step 3: Cross multiply
    639.96x = 882.98 × 391.19
  4. Step 4: Simplify right side
    639.96x = 345,411.48
  5. Step 5: Solve for x
    x = 345,411.48/639.96
  6. Step 6: Final answer
    x = 539.74

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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.