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Finding the Fourth Proportional to 726.87, 1,002.80 and 478.31

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Solution

The fourth proportional to 726.87, 1,002.80 and 478.31 is: 659.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    726.87 : 1,002.80 = 478.31 : x
  2. Step 2: Convert to fraction form
    726.87/1,002.80 = 478.31/x
  3. Step 3: Cross multiply
    726.87x = 1,002.80 × 478.31
  4. Step 4: Simplify right side
    726.87x = 479,646.88
  5. Step 5: Solve for x
    x = 479,646.88/726.87
  6. Step 6: Final answer
    x = 659.88

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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.