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Finding the Fourth Proportional to 812.18, 1,120.81 and 439.16

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Solution

The fourth proportional to 812.18, 1,120.81 and 439.16 is: 606.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.18 : 1,120.81 = 439.16 : x
  2. Step 2: Convert to fraction form
    812.18/1,120.81 = 439.16/x
  3. Step 3: Cross multiply
    812.18x = 1,120.81 × 439.16
  4. Step 4: Simplify right side
    812.18x = 492,217.17
  5. Step 5: Solve for x
    x = 492,217.17/812.18
  6. Step 6: Final answer
    x = 606.04

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.