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Finding the Fourth Proportional to 429.17, 643.74 and 140.61

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Solution

The fourth proportional to 429.17, 643.74 and 140.61 is: 210.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.17 : 643.74 = 140.61 : x
  2. Step 2: Convert to fraction form
    429.17/643.74 = 140.61/x
  3. Step 3: Cross multiply
    429.17x = 643.74 × 140.61
  4. Step 4: Simplify right side
    429.17x = 90,516.28
  5. Step 5: Solve for x
    x = 90,516.28/429.17
  6. Step 6: Final answer
    x = 210.91

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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.