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Finding the Fourth Proportional to 812.59, 1,217.28 and 422.84

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Solution

The fourth proportional to 812.59, 1,217.28 and 422.84 is: 633.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.59 : 1,217.28 = 422.84 : x
  2. Step 2: Convert to fraction form
    812.59/1,217.28 = 422.84/x
  3. Step 3: Cross multiply
    812.59x = 1,217.28 × 422.84
  4. Step 4: Simplify right side
    812.59x = 514,714.68
  5. Step 5: Solve for x
    x = 514,714.68/812.59
  6. Step 6: Final answer
    x = 633.42

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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.