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Finding the Fourth Proportional to 720.29, 1,080.40 and 355.31

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Solution

The fourth proportional to 720.29, 1,080.40 and 355.31 is: 532.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.29 : 1,080.40 = 355.31 : x
  2. Step 2: Convert to fraction form
    720.29/1,080.40 = 355.31/x
  3. Step 3: Cross multiply
    720.29x = 1,080.40 × 355.31
  4. Step 4: Simplify right side
    720.29x = 383,876.92
  5. Step 5: Solve for x
    x = 383,876.92/720.29
  6. Step 6: Final answer
    x = 532.95

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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.