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Finding the Fourth Proportional to 721.13, 1,081.80 and 282.31

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Solution

The fourth proportional to 721.13, 1,081.80 and 282.31 is: 423.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.13 : 1,081.80 = 282.31 : x
  2. Step 2: Convert to fraction form
    721.13/1,081.80 = 282.31/x
  3. Step 3: Cross multiply
    721.13x = 1,081.80 × 282.31
  4. Step 4: Simplify right side
    721.13x = 305,400.25
  5. Step 5: Solve for x
    x = 305,400.25/721.13
  6. Step 6: Final answer
    x = 423.50

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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.