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Finding the Fourth Proportional to 905.15, 1,249.11 and 512.20

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Solution

The fourth proportional to 905.15, 1,249.11 and 512.20 is: 706.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.15 : 1,249.11 = 512.20 : x
  2. Step 2: Convert to fraction form
    905.15/1,249.11 = 512.20/x
  3. Step 3: Cross multiply
    905.15x = 1,249.11 × 512.20
  4. Step 4: Simplify right side
    905.15x = 639,794.14
  5. Step 5: Solve for x
    x = 639,794.14/905.15
  6. Step 6: Final answer
    x = 706.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.