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Finding the Third Proportional to 138.88 and 218.19

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Solution

The third proportional to 138.88 and 218.19 is: 342.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.88 : 218.19 = 218.19 : x
  2. Step 2: Convert to fraction form
    138.88/218.19 = 218.19/x
  3. Step 3: Cross multiply
    138.88x = 218.19 × 218.19
  4. Step 4: Simplify right side
    138.88x = 47,605.79
  5. Step 5: Solve for x
    x = 47,605.79/138.88
  6. Step 6: Final answer
    x = 342.80

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Why These Related Problems?

These problems maintain the same ratio (1.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.