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Finding the Third Proportional to 77 and 115

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Solution

The third proportional to 77 and 115 is: 171.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    77 : 115 = 115 : x
  2. Step 2: Convert to fraction form
    77/115 = 115/x
  3. Step 3: Cross multiply
    77x = 115 × 115
  4. Step 4: Simplify right side
    77x = 13,225
  5. Step 5: Solve for x
    x = 13,225/77
  6. Step 6: Final answer
    x = 171.75

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.