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Finding the Fourth Proportional to 421.89, 631.91 and 411.56

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Solution

The fourth proportional to 421.89, 631.91 and 411.56 is: 616.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.89 : 631.91 = 411.56 : x
  2. Step 2: Convert to fraction form
    421.89/631.91 = 411.56/x
  3. Step 3: Cross multiply
    421.89x = 631.91 × 411.56
  4. Step 4: Simplify right side
    421.89x = 260,063.66
  5. Step 5: Solve for x
    x = 260,063.66/421.89
  6. Step 6: Final answer
    x = 616.43

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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.