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Finding the Fourth Proportional to 724.78, 999.30 and 491.50

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Solution

The fourth proportional to 724.78, 999.30 and 491.50 is: 677.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.78 : 999.30 = 491.50 : x
  2. Step 2: Convert to fraction form
    724.78/999.30 = 491.50/x
  3. Step 3: Cross multiply
    724.78x = 999.30 × 491.50
  4. Step 4: Simplify right side
    724.78x = 491,155.95
  5. Step 5: Solve for x
    x = 491,155.95/724.78
  6. Step 6: Final answer
    x = 677.66

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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.