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Finding the Fourth Proportional to 229.91, 345.20 and 138.71

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Solution

The fourth proportional to 229.91, 345.20 and 138.71 is: 208.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    229.91 : 345.20 = 138.71 : x
  2. Step 2: Convert to fraction form
    229.91/345.20 = 138.71/x
  3. Step 3: Cross multiply
    229.91x = 345.20 × 138.71
  4. Step 4: Simplify right side
    229.91x = 47,882.86
  5. Step 5: Solve for x
    x = 47,882.86/229.91
  6. Step 6: Final answer
    x = 208.27

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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.