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Finding the Fourth Proportional to 721.17, 1,080.85 and 309.83

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Solution

The fourth proportional to 721.17, 1,080.85 and 309.83 is: 464.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.17 : 1,080.85 = 309.83 : x
  2. Step 2: Convert to fraction form
    721.17/1,080.85 = 309.83/x
  3. Step 3: Cross multiply
    721.17x = 1,080.85 × 309.83
  4. Step 4: Simplify right side
    721.17x = 334,879.76
  5. Step 5: Solve for x
    x = 334,879.76/721.17
  6. Step 6: Final answer
    x = 464.36

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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.