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Finding the Fourth Proportional to 721.42, 993.81 and 499.99

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Solution

The fourth proportional to 721.42, 993.81 and 499.99 is: 688.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.42 : 993.81 = 499.99 : x
  2. Step 2: Convert to fraction form
    721.42/993.81 = 499.99/x
  3. Step 3: Cross multiply
    721.42x = 993.81 × 499.99
  4. Step 4: Simplify right side
    721.42x = 496,895.06
  5. Step 5: Solve for x
    x = 496,895.06/721.42
  6. Step 6: Final answer
    x = 688.77

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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.