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Finding the Fourth Proportional to 665.92, 997.26 and 421.72

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Solution

The fourth proportional to 665.92, 997.26 and 421.72 is: 631.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.92 : 997.26 = 421.72 : x
  2. Step 2: Convert to fraction form
    665.92/997.26 = 421.72/x
  3. Step 3: Cross multiply
    665.92x = 997.26 × 421.72
  4. Step 4: Simplify right side
    665.92x = 420,564.49
  5. Step 5: Solve for x
    x = 420,564.49/665.92
  6. Step 6: Final answer
    x = 631.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.