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Finding the Fourth Proportional to 721.69, 1,080.80 and 412.61

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Solution

The fourth proportional to 721.69, 1,080.80 and 412.61 is: 617.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.69 : 1,080.80 = 412.61 : x
  2. Step 2: Convert to fraction form
    721.69/1,080.80 = 412.61/x
  3. Step 3: Cross multiply
    721.69x = 1,080.80 × 412.61
  4. Step 4: Simplify right side
    721.69x = 445,943.48
  5. Step 5: Solve for x
    x = 445,943.48/721.69
  6. Step 6: Final answer
    x = 617.92

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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.