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Finding the Fourth Proportional to 207.38, 311.14 and 138.71

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Solution

The fourth proportional to 207.38, 311.14 and 138.71 is: 208.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.38 : 311.14 = 138.71 : x
  2. Step 2: Convert to fraction form
    207.38/311.14 = 138.71/x
  3. Step 3: Cross multiply
    207.38x = 311.14 × 138.71
  4. Step 4: Simplify right side
    207.38x = 43,158.23
  5. Step 5: Solve for x
    x = 43,158.23/207.38
  6. Step 6: Final answer
    x = 208.11

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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.