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Finding the Fourth Proportional to 721.86, 1,081.98 and 311.19

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Solution

The fourth proportional to 721.86, 1,081.98 and 311.19 is: 466.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.86 : 1,081.98 = 311.19 : x
  2. Step 2: Convert to fraction form
    721.86/1,081.98 = 311.19/x
  3. Step 3: Cross multiply
    721.86x = 1,081.98 × 311.19
  4. Step 4: Simplify right side
    721.86x = 336,701.36
  5. Step 5: Solve for x
    x = 336,701.36/721.86
  6. Step 6: Final answer
    x = 466.44

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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.