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Finding the Third Proportional to 138.42 and 299.91

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Solution

The third proportional to 138.42 and 299.91 is: 649.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.42 : 299.91 = 299.91 : x
  2. Step 2: Convert to fraction form
    138.42/299.91 = 299.91/x
  3. Step 3: Cross multiply
    138.42x = 299.91 × 299.91
  4. Step 4: Simplify right side
    138.42x = 89,943.76
  5. Step 5: Solve for x
    x = 89,943.76/138.42
  6. Step 6: Final answer
    x = 649.78

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Why These Related Problems?

These problems maintain the same ratio (2.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.