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Finding the Fourth Proportional to 330.20, 495.30 and 137.80

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Solution

The fourth proportional to 330.20, 495.30 and 137.80 is: 206.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    330.20 : 495.30 = 137.80 : x
  2. Step 2: Convert to fraction form
    330.20/495.30 = 137.80/x
  3. Step 3: Cross multiply
    330.20x = 495.30 × 137.80
  4. Step 4: Simplify right side
    330.20x = 68,252.34
  5. Step 5: Solve for x
    x = 68,252.34/330.20
  6. Step 6: Final answer
    x = 206.70

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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.