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Finding the Fourth Proportional to 641.28, 961.98 and 256.56

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Solution

The fourth proportional to 641.28, 961.98 and 256.56 is: 384.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.28 : 961.98 = 256.56 : x
  2. Step 2: Convert to fraction form
    641.28/961.98 = 256.56/x
  3. Step 3: Cross multiply
    641.28x = 961.98 × 256.56
  4. Step 4: Simplify right side
    641.28x = 246,805.59
  5. Step 5: Solve for x
    x = 246,805.59/641.28
  6. Step 6: Final answer
    x = 384.86

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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.