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Finding the Fourth Proportional to 641.87, 961.40 and 394.32

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Solution

The fourth proportional to 641.87, 961.40 and 394.32 is: 590.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.87 : 961.40 = 394.32 : x
  2. Step 2: Convert to fraction form
    641.87/961.40 = 394.32/x
  3. Step 3: Cross multiply
    641.87x = 961.40 × 394.32
  4. Step 4: Simplify right side
    641.87x = 379,099.25
  5. Step 5: Solve for x
    x = 379,099.25/641.87
  6. Step 6: Final answer
    x = 590.62

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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.