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Finding the Fourth Proportional to 720.96, 1,081.42 and 309.89

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Solution

The fourth proportional to 720.96, 1,081.42 and 309.89 is: 464.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.96 : 1,081.42 = 309.89 : x
  2. Step 2: Convert to fraction form
    720.96/1,081.42 = 309.89/x
  3. Step 3: Cross multiply
    720.96x = 1,081.42 × 309.89
  4. Step 4: Simplify right side
    720.96x = 335,121.24
  5. Step 5: Solve for x
    x = 335,121.24/720.96
  6. Step 6: Final answer
    x = 464.83

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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.