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Finding the Fourth Proportional to 721.65, 1,080.78 and 355.26

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Solution

The fourth proportional to 721.65, 1,080.78 and 355.26 is: 532.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.65 : 1,080.78 = 355.26 : x
  2. Step 2: Convert to fraction form
    721.65/1,080.78 = 355.26/x
  3. Step 3: Cross multiply
    721.65x = 1,080.78 × 355.26
  4. Step 4: Simplify right side
    721.65x = 383,957.90
  5. Step 5: Solve for x
    x = 383,957.90/721.65
  6. Step 6: Final answer
    x = 532.06

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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.