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Finding the Fourth Proportional to 641.28, 961.78 and 251.16

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Solution

The fourth proportional to 641.28, 961.78 and 251.16 is: 376.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.28 : 961.78 = 251.16 : x
  2. Step 2: Convert to fraction form
    641.28/961.78 = 251.16/x
  3. Step 3: Cross multiply
    641.28x = 961.78 × 251.16
  4. Step 4: Simplify right side
    641.28x = 241,560.66
  5. Step 5: Solve for x
    x = 241,560.66/641.28
  6. Step 6: Final answer
    x = 376.69

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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.