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Finding the Fourth Proportional to 726.80, 1,003.20 and 478.31

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Solution

The fourth proportional to 726.80, 1,003.20 and 478.31 is: 660.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    726.80 : 1,003.20 = 478.31 : x
  2. Step 2: Convert to fraction form
    726.80/1,003.20 = 478.31/x
  3. Step 3: Cross multiply
    726.80x = 1,003.20 × 478.31
  4. Step 4: Simplify right side
    726.80x = 479,840.59
  5. Step 5: Solve for x
    x = 479,840.59/726.80
  6. Step 6: Final answer
    x = 660.21

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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.