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Finding the Fourth Proportional to 781, 1,077.54 and 515.86

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Solution

The fourth proportional to 781, 1,077.54 and 515.86 is: 711.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    781 : 1,077.54 = 515.86 : x
  2. Step 2: Convert to fraction form
    781/1,077.54 = 515.86/x
  3. Step 3: Cross multiply
    781x = 1,077.54 × 515.86
  4. Step 4: Simplify right side
    781x = 555,859.78
  5. Step 5: Solve for x
    x = 555,859.78/781
  6. Step 6: Final answer
    x = 711.73

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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.