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Finding the Fourth Proportional to 429.55, 643.09 and 385.03

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Solution

The fourth proportional to 429.55, 643.09 and 385.03 is: 576.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.55 : 643.09 = 385.03 : x
  2. Step 2: Convert to fraction form
    429.55/643.09 = 385.03/x
  3. Step 3: Cross multiply
    429.55x = 643.09 × 385.03
  4. Step 4: Simplify right side
    429.55x = 247,608.94
  5. Step 5: Solve for x
    x = 247,608.94/429.55
  6. Step 6: Final answer
    x = 576.44

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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.