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Finding the Fourth Proportional to 814.87, 1,124.67 and 639.91

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Solution

The fourth proportional to 814.87, 1,124.67 and 639.91 is: 883.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.87 : 1,124.67 = 639.91 : x
  2. Step 2: Convert to fraction form
    814.87/1,124.67 = 639.91/x
  3. Step 3: Cross multiply
    814.87x = 1,124.67 × 639.91
  4. Step 4: Simplify right side
    814.87x = 719,691.39
  5. Step 5: Solve for x
    x = 719,691.39/814.87
  6. Step 6: Final answer
    x = 883.20

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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.