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Finding the Fourth Proportional to 721.32, 1,081.90 and 447.45

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Solution

The fourth proportional to 721.32, 1,081.90 and 447.45 is: 671.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.32 : 1,081.90 = 447.45 : x
  2. Step 2: Convert to fraction form
    721.32/1,081.90 = 447.45/x
  3. Step 3: Cross multiply
    721.32x = 1,081.90 × 447.45
  4. Step 4: Simplify right side
    721.32x = 484,096.16
  5. Step 5: Solve for x
    x = 484,096.16/721.32
  6. Step 6: Final answer
    x = 671.13

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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.