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Finding the Fourth Proportional to 512.55, 768.78 and 127.80

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Solution

The fourth proportional to 512.55, 768.78 and 127.80 is: 191.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.55 : 768.78 = 127.80 : x
  2. Step 2: Convert to fraction form
    512.55/768.78 = 127.80/x
  3. Step 3: Cross multiply
    512.55x = 768.78 × 127.80
  4. Step 4: Simplify right side
    512.55x = 98,250.08
  5. Step 5: Solve for x
    x = 98,250.08/512.55
  6. Step 6: Final answer
    x = 191.69

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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.