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Finding the Fourth Proportional to 721.11, 1,081.65 and 288.25

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Solution

The fourth proportional to 721.11, 1,081.65 and 288.25 is: 432.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.11 : 1,081.65 = 288.25 : x
  2. Step 2: Convert to fraction form
    721.11/1,081.65 = 288.25/x
  3. Step 3: Cross multiply
    721.11x = 1,081.65 × 288.25
  4. Step 4: Simplify right side
    721.11x = 311,785.61
  5. Step 5: Solve for x
    x = 311,785.61/721.11
  6. Step 6: Final answer
    x = 432.37

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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.