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Finding the Fourth Proportional to 717.29, 989.91 and 422.78

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Solution

The fourth proportional to 717.29, 989.91 and 422.78 is: 583.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.29 : 989.91 = 422.78 : x
  2. Step 2: Convert to fraction form
    717.29/989.91 = 422.78/x
  3. Step 3: Cross multiply
    717.29x = 989.91 × 422.78
  4. Step 4: Simplify right side
    717.29x = 418,512.04
  5. Step 5: Solve for x
    x = 418,512.04/717.29
  6. Step 6: Final answer
    x = 583.47

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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.