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Finding the Fourth Proportional to 641.39, 960.78 and 511.61

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Solution

The fourth proportional to 641.39, 960.78 and 511.61 is: 766.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.39 : 960.78 = 511.61 : x
  2. Step 2: Convert to fraction form
    641.39/960.78 = 511.61/x
  3. Step 3: Cross multiply
    641.39x = 960.78 × 511.61
  4. Step 4: Simplify right side
    641.39x = 491,544.66
  5. Step 5: Solve for x
    x = 491,544.66/641.39
  6. Step 6: Final answer
    x = 766.37

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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.