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Finding the Third Proportional to 39 and 66

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Solution

The third proportional to 39 and 66 is: 111.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    39 : 66 = 66 : x
  2. Step 2: Convert to fraction form
    39/66 = 66/x
  3. Step 3: Cross multiply
    39x = 66 × 66
  4. Step 4: Simplify right side
    39x = 4,356
  5. Step 5: Solve for x
    x = 4,356/39
  6. Step 6: Final answer
    x = 111.69

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Why These Related Problems?

These problems maintain the same ratio (1.69) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.