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Finding the Fourth Proportional to 724.88, 999.20 and 491.60

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Solution

The fourth proportional to 724.88, 999.20 and 491.60 is: 677.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.88 : 999.20 = 491.60 : x
  2. Step 2: Convert to fraction form
    724.88/999.20 = 491.60/x
  3. Step 3: Cross multiply
    724.88x = 999.20 × 491.60
  4. Step 4: Simplify right side
    724.88x = 491,206.72
  5. Step 5: Solve for x
    x = 491,206.72/724.88
  6. Step 6: Final answer
    x = 677.64

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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.