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Finding the Fourth Proportional to 429.08, 643.46 and 140.45

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Solution

The fourth proportional to 429.08, 643.46 and 140.45 is: 210.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.08 : 643.46 = 140.45 : x
  2. Step 2: Convert to fraction form
    429.08/643.46 = 140.45/x
  3. Step 3: Cross multiply
    429.08x = 643.46 × 140.45
  4. Step 4: Simplify right side
    429.08x = 90,370.04
  5. Step 5: Solve for x
    x = 90,370.04/429.08
  6. Step 6: Final answer
    x = 210.62

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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.