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Finding the Third Proportional to 64.50 and 138.75

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Solution

The third proportional to 64.50 and 138.75 is: 298.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.50 : 138.75 = 138.75 : x
  2. Step 2: Convert to fraction form
    64.50/138.75 = 138.75/x
  3. Step 3: Cross multiply
    64.50x = 138.75 × 138.75
  4. Step 4: Simplify right side
    64.50x = 19,251.56
  5. Step 5: Solve for x
    x = 19,251.56/64.50
  6. Step 6: Final answer
    x = 298.47

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Why These Related Problems?

These problems maintain the same ratio (2.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.