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Finding the Fourth Proportional to 717.52, 990.20 and 422.80

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Solution

The fourth proportional to 717.52, 990.20 and 422.80 is: 583.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.52 : 990.20 = 422.80 : x
  2. Step 2: Convert to fraction form
    717.52/990.20 = 422.80/x
  3. Step 3: Cross multiply
    717.52x = 990.20 × 422.80
  4. Step 4: Simplify right side
    717.52x = 418,656.56
  5. Step 5: Solve for x
    x = 418,656.56/717.52
  6. Step 6: Final answer
    x = 583.48

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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.