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Finding the Fourth Proportional to 865.77, 1,298.64 and 519.20

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Solution

The fourth proportional to 865.77, 1,298.64 and 519.20 is: 778.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.77 : 1,298.64 = 519.20 : x
  2. Step 2: Convert to fraction form
    865.77/1,298.64 = 519.20/x
  3. Step 3: Cross multiply
    865.77x = 1,298.64 × 519.20
  4. Step 4: Simplify right side
    865.77x = 674,247.39
  5. Step 5: Solve for x
    x = 674,247.39/865.77
  6. Step 6: Final answer
    x = 778.78

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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.