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Finding the Fourth Proportional to 723.70, 998.40 and 428.86

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Solution

The fourth proportional to 723.70, 998.40 and 428.86 is: 591.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.70 : 998.40 = 428.86 : x
  2. Step 2: Convert to fraction form
    723.70/998.40 = 428.86/x
  3. Step 3: Cross multiply
    723.70x = 998.40 × 428.86
  4. Step 4: Simplify right side
    723.70x = 428,173.82
  5. Step 5: Solve for x
    x = 428,173.82/723.70
  6. Step 6: Final answer
    x = 591.65

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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.