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Finding the Fourth Proportional to 640.78, 961.16 and 178.57

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Solution

The fourth proportional to 640.78, 961.16 and 178.57 is: 267.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.78 : 961.16 = 178.57 : x
  2. Step 2: Convert to fraction form
    640.78/961.16 = 178.57/x
  3. Step 3: Cross multiply
    640.78x = 961.16 × 178.57
  4. Step 4: Simplify right side
    640.78x = 171,634.34
  5. Step 5: Solve for x
    x = 171,634.34/640.78
  6. Step 6: Final answer
    x = 267.85

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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.