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Finding the Fourth Proportional to 720.73, 1,081.23 and 287.89

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Solution

The fourth proportional to 720.73, 1,081.23 and 287.89 is: 431.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.73 : 1,081.23 = 287.89 : x
  2. Step 2: Convert to fraction form
    720.73/1,081.23 = 287.89/x
  3. Step 3: Cross multiply
    720.73x = 1,081.23 × 287.89
  4. Step 4: Simplify right side
    720.73x = 311,275.30
  5. Step 5: Solve for x
    x = 311,275.30/720.73
  6. Step 6: Final answer
    x = 431.89

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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.