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Finding the Fourth Proportional to 721.56, 1,081.77 and 331.81

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Solution

The fourth proportional to 721.56, 1,081.77 and 331.81 is: 497.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.56 : 1,081.77 = 331.81 : x
  2. Step 2: Convert to fraction form
    721.56/1,081.77 = 331.81/x
  3. Step 3: Cross multiply
    721.56x = 1,081.77 × 331.81
  4. Step 4: Simplify right side
    721.56x = 358,942.10
  5. Step 5: Solve for x
    x = 358,942.10/721.56
  6. Step 6: Final answer
    x = 497.45

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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.