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Finding the Fourth Proportional to 679.87, 938.32 and 431.21

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Solution

The fourth proportional to 679.87, 938.32 and 431.21 is: 595.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.87 : 938.32 = 431.21 : x
  2. Step 2: Convert to fraction form
    679.87/938.32 = 431.21/x
  3. Step 3: Cross multiply
    679.87x = 938.32 × 431.21
  4. Step 4: Simplify right side
    679.87x = 404,612.97
  5. Step 5: Solve for x
    x = 404,612.97/679.87
  6. Step 6: Final answer
    x = 595.13

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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.