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Finding the Fourth Proportional to 721.16, 1,081.11 and 288.03

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Solution

The fourth proportional to 721.16, 1,081.11 and 288.03 is: 431.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.16 : 1,081.11 = 288.03 : x
  2. Step 2: Convert to fraction form
    721.16/1,081.11 = 288.03/x
  3. Step 3: Cross multiply
    721.16x = 1,081.11 × 288.03
  4. Step 4: Simplify right side
    721.16x = 311,392.11
  5. Step 5: Solve for x
    x = 311,392.11/721.16
  6. Step 6: Final answer
    x = 431.79

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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.