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Finding the Fourth Proportional to 812, 1,218.30 and 487.60

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Solution

The fourth proportional to 812, 1,218.30 and 487.60 is: 731.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    812 : 1,218.30 = 487.60 : x
  2. Step 2: Convert to fraction form
    812/1,218.30 = 487.60/x
  3. Step 3: Cross multiply
    812x = 1,218.30 × 487.60
  4. Step 4: Simplify right side
    812x = 594,043.08
  5. Step 5: Solve for x
    x = 594,043.08/812
  6. Step 6: Final answer
    x = 731.58

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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.