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Finding the Fourth Proportional to 812.61, 1,218.87 and 553.10

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Solution

The fourth proportional to 812.61, 1,218.87 and 553.10 is: 829.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.61 : 1,218.87 = 553.10 : x
  2. Step 2: Convert to fraction form
    812.61/1,218.87 = 553.10/x
  3. Step 3: Cross multiply
    812.61x = 1,218.87 × 553.10
  4. Step 4: Simplify right side
    812.61x = 674,150.90
  5. Step 5: Solve for x
    x = 674,150.90/812.61
  6. Step 6: Final answer
    x = 829.61

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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.