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Finding the Fourth Proportional to 812.52, 1,219.50 and 422.80

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Solution

The fourth proportional to 812.52, 1,219.50 and 422.80 is: 634.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.52 : 1,219.50 = 422.80 : x
  2. Step 2: Convert to fraction form
    812.52/1,219.50 = 422.80/x
  3. Step 3: Cross multiply
    812.52x = 1,219.50 × 422.80
  4. Step 4: Simplify right side
    812.52x = 515,601.55
  5. Step 5: Solve for x
    x = 515,601.55/812.52
  6. Step 6: Final answer
    x = 634.57

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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.