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Finding the Fourth Proportional to 422.78, 634.32 and 191.72

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Solution

The fourth proportional to 422.78, 634.32 and 191.72 is: 287.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.78 : 634.32 = 191.72 : x
  2. Step 2: Convert to fraction form
    422.78/634.32 = 191.72/x
  3. Step 3: Cross multiply
    422.78x = 634.32 × 191.72
  4. Step 4: Simplify right side
    422.78x = 121,611.83
  5. Step 5: Solve for x
    x = 121,611.83/422.78
  6. Step 6: Final answer
    x = 287.65

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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.