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Finding the Fourth Proportional to 812.12, 1,217.36 and 401.55

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Solution

The fourth proportional to 812.12, 1,217.36 and 401.55 is: 601.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.12 : 1,217.36 = 401.55 : x
  2. Step 2: Convert to fraction form
    812.12/1,217.36 = 401.55/x
  3. Step 3: Cross multiply
    812.12x = 1,217.36 × 401.55
  4. Step 4: Simplify right side
    812.12x = 488,824.82
  5. Step 5: Solve for x
    x = 488,824.82/812.12
  6. Step 6: Final answer
    x = 601.92

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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.