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Finding the Fourth Proportional to 812.11, 1,120.20 and 613.25

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Solution

The fourth proportional to 812.11, 1,120.20 and 613.25 is: 845.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.11 : 1,120.20 = 613.25 : x
  2. Step 2: Convert to fraction form
    812.11/1,120.20 = 613.25/x
  3. Step 3: Cross multiply
    812.11x = 1,120.20 × 613.25
  4. Step 4: Simplify right side
    812.11x = 686,962.65
  5. Step 5: Solve for x
    x = 686,962.65/812.11
  6. Step 6: Final answer
    x = 845.90

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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.