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Finding the Fourth Proportional to 717.20, 989.50 and 418.38

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Solution

The fourth proportional to 717.20, 989.50 and 418.38 is: 577.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.20 : 989.50 = 418.38 : x
  2. Step 2: Convert to fraction form
    717.20/989.50 = 418.38/x
  3. Step 3: Cross multiply
    717.20x = 989.50 × 418.38
  4. Step 4: Simplify right side
    717.20x = 413,979.97
  5. Step 5: Solve for x
    x = 413,979.97/717.20
  6. Step 6: Final answer
    x = 577.22

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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.