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Finding the Fourth Proportional to 723.11, 997.90 and 428.40

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Solution

The fourth proportional to 723.11, 997.90 and 428.40 is: 591.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.11 : 997.90 = 428.40 : x
  2. Step 2: Convert to fraction form
    723.11/997.90 = 428.40/x
  3. Step 3: Cross multiply
    723.11x = 997.90 × 428.40
  4. Step 4: Simplify right side
    723.11x = 427,498.22
  5. Step 5: Solve for x
    x = 427,498.22/723.11
  6. Step 6: Final answer
    x = 591.19

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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.