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Finding the Fourth Proportional to 512.78, 769.30 and 239.05

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Solution

The fourth proportional to 512.78, 769.30 and 239.05 is: 358.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.78 : 769.30 = 239.05 : x
  2. Step 2: Convert to fraction form
    512.78/769.30 = 239.05/x
  3. Step 3: Cross multiply
    512.78x = 769.30 × 239.05
  4. Step 4: Simplify right side
    512.78x = 183,901.53
  5. Step 5: Solve for x
    x = 183,901.53/512.78
  6. Step 6: Final answer
    x = 358.64

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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.