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Finding the Fourth Proportional to 641.28, 891.20 and 634.24

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Solution

The fourth proportional to 641.28, 891.20 and 634.24 is: 881.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.28 : 891.20 = 634.24 : x
  2. Step 2: Convert to fraction form
    641.28/891.20 = 634.24/x
  3. Step 3: Cross multiply
    641.28x = 891.20 × 634.24
  4. Step 4: Simplify right side
    641.28x = 565,234.69
  5. Step 5: Solve for x
    x = 565,234.69/641.28
  6. Step 6: Final answer
    x = 881.42

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.