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Finding the Fourth Proportional to 429.78, 641.18 and 394.54

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Solution

The fourth proportional to 429.78, 641.18 and 394.54 is: 588.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.78 : 641.18 = 394.54 : x
  2. Step 2: Convert to fraction form
    429.78/641.18 = 394.54/x
  3. Step 3: Cross multiply
    429.78x = 641.18 × 394.54
  4. Step 4: Simplify right side
    429.78x = 252,971.16
  5. Step 5: Solve for x
    x = 252,971.16/429.78
  6. Step 6: Final answer
    x = 588.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.