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Finding the Fourth Proportional to 380.70, 571.28 and 137.20

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Solution

The fourth proportional to 380.70, 571.28 and 137.20 is: 205.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.70 : 571.28 = 137.20 : x
  2. Step 2: Convert to fraction form
    380.70/571.28 = 137.20/x
  3. Step 3: Cross multiply
    380.70x = 571.28 × 137.20
  4. Step 4: Simplify right side
    380.70x = 78,379.62
  5. Step 5: Solve for x
    x = 78,379.62/380.70
  6. Step 6: Final answer
    x = 205.88

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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.