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Finding the Fourth Proportional to 512.80, 769.20 and 128.06

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Solution

The fourth proportional to 512.80, 769.20 and 128.06 is: 192.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.80 : 769.20 = 128.06 : x
  2. Step 2: Convert to fraction form
    512.80/769.20 = 128.06/x
  3. Step 3: Cross multiply
    512.80x = 769.20 × 128.06
  4. Step 4: Simplify right side
    512.80x = 98,503.75
  5. Step 5: Solve for x
    x = 98,503.75/512.80
  6. Step 6: Final answer
    x = 192.09

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Double scale
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Similar ratio
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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.