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Finding the Fourth Proportional to 512.80, 769.20 and 330.40

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Solution

The fourth proportional to 512.80, 769.20 and 330.40 is: 495.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.80 : 769.20 = 330.40 : x
  2. Step 2: Convert to fraction form
    512.80/769.20 = 330.40/x
  3. Step 3: Cross multiply
    512.80x = 769.20 × 330.40
  4. Step 4: Simplify right side
    512.80x = 254,143.68
  5. Step 5: Solve for x
    x = 254,143.68/512.80
  6. Step 6: Final answer
    x = 495.60

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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.