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Finding the Fourth Proportional to 721.24, 993.93 and 499.78

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Solution

The fourth proportional to 721.24, 993.93 and 499.78 is: 688.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.24 : 993.93 = 499.78 : x
  2. Step 2: Convert to fraction form
    721.24/993.93 = 499.78/x
  3. Step 3: Cross multiply
    721.24x = 993.93 × 499.78
  4. Step 4: Simplify right side
    721.24x = 496,746.34
  5. Step 5: Solve for x
    x = 496,746.34/721.24
  6. Step 6: Final answer
    x = 688.74

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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.