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Finding the Third Proportional to 78 and 104

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Solution

The third proportional to 78 and 104 is: 138.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    78 : 104 = 104 : x
  2. Step 2: Convert to fraction form
    78/104 = 104/x
  3. Step 3: Cross multiply
    78x = 104 × 104
  4. Step 4: Simplify right side
    78x = 10,816
  5. Step 5: Solve for x
    x = 10,816/78
  6. Step 6: Final answer
    x = 138.67

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Why These Related Problems?

These problems maintain the same ratio (1.33) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.