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Finding the Third Proportional to 31.80 and 67.87

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Solution

The third proportional to 31.80 and 67.87 is: 144.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.80 : 67.87 = 67.87 : x
  2. Step 2: Convert to fraction form
    31.80/67.87 = 67.87/x
  3. Step 3: Cross multiply
    31.80x = 67.87 × 67.87
  4. Step 4: Simplify right side
    31.80x = 4,606.22
  5. Step 5: Solve for x
    x = 4,606.22/31.80
  6. Step 6: Final answer
    x = 144.86

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Why These Related Problems?

These problems maintain the same ratio (2.13) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.