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Finding the Fourth Proportional to 781.91, 1,078.92 and 760.91

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Solution

The fourth proportional to 781.91, 1,078.92 and 760.91 is: 1,049.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.91 : 1,078.92 = 760.91 : x
  2. Step 2: Convert to fraction form
    781.91/1,078.92 = 760.91/x
  3. Step 3: Cross multiply
    781.91x = 1,078.92 × 760.91
  4. Step 4: Simplify right side
    781.91x = 820,961.02
  5. Step 5: Solve for x
    x = 820,961.02/781.91
  6. Step 6: Final answer
    x = 1,049.94

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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.