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Finding the Fourth Proportional to 721.09, 1,081 and 612.11

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Solution

The fourth proportional to 721.09, 1,081 and 612.11 is: 917.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.09 : 1,081 = 612.11 : x
  2. Step 2: Convert to fraction form
    721.09/1,081 = 612.11/x
  3. Step 3: Cross multiply
    721.09x = 1,081 × 612.11
  4. Step 4: Simplify right side
    721.09x = 661,690.91
  5. Step 5: Solve for x
    x = 661,690.91/721.09
  6. Step 6: Final answer
    x = 917.63

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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.