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Finding the Fourth Proportional to 641.62, 961.50 and 381.40

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Solution

The fourth proportional to 641.62, 961.50 and 381.40 is: 571.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.62 : 961.50 = 381.40 : x
  2. Step 2: Convert to fraction form
    641.62/961.50 = 381.40/x
  3. Step 3: Cross multiply
    641.62x = 961.50 × 381.40
  4. Step 4: Simplify right side
    641.62x = 366,716.10
  5. Step 5: Solve for x
    x = 366,716.10/641.62
  6. Step 6: Final answer
    x = 571.55

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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.