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Finding the Fourth Proportional to 629.88, 868.08 and 487.90

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Solution

The fourth proportional to 629.88, 868.08 and 487.90 is: 672.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.88 : 868.08 = 487.90 : x
  2. Step 2: Convert to fraction form
    629.88/868.08 = 487.90/x
  3. Step 3: Cross multiply
    629.88x = 868.08 × 487.90
  4. Step 4: Simplify right side
    629.88x = 423,534.65
  5. Step 5: Solve for x
    x = 423,534.65/629.88
  6. Step 6: Final answer
    x = 672.40

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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.