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Finding the Fourth Proportional to 905.70, 1,249.92 and 512.70

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Solution

The fourth proportional to 905.70, 1,249.92 and 512.70 is: 707.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.70 : 1,249.92 = 512.70 : x
  2. Step 2: Convert to fraction form
    905.70/1,249.92 = 512.70/x
  3. Step 3: Cross multiply
    905.70x = 1,249.92 × 512.70
  4. Step 4: Simplify right side
    905.70x = 640,833.98
  5. Step 5: Solve for x
    x = 640,833.98/905.70
  6. Step 6: Final answer
    x = 707.56

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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.