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Finding the Third Proportional to 39 and 78.38

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Solution

The third proportional to 39 and 78.38 is: 157.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    39 : 78.38 = 78.38 : x
  2. Step 2: Convert to fraction form
    39/78.38 = 78.38/x
  3. Step 3: Cross multiply
    39x = 78.38 × 78.38
  4. Step 4: Simplify right side
    39x = 6,142.64
  5. Step 5: Solve for x
    x = 6,142.64/39
  6. Step 6: Final answer
    x = 157.50

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Why These Related Problems?

These problems maintain the same ratio (2.01) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.