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Finding the Fourth Proportional to 429.21, 644.03 and 209.74

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Solution

The fourth proportional to 429.21, 644.03 and 209.74 is: 314.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.21 : 644.03 = 209.74 : x
  2. Step 2: Convert to fraction form
    429.21/644.03 = 209.74/x
  3. Step 3: Cross multiply
    429.21x = 644.03 × 209.74
  4. Step 4: Simplify right side
    429.21x = 135,074.58
  5. Step 5: Solve for x
    x = 135,074.58/429.21
  6. Step 6: Final answer
    x = 314.71

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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.