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Finding the Third Proportional to 100 and 115

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Solution

The third proportional to 100 and 115 is: 132.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    100 : 115 = 115 : x
  2. Step 2: Convert to fraction form
    100/115 = 115/x
  3. Step 3: Cross multiply
    100x = 115 × 115
  4. Step 4: Simplify right side
    100x = 13,225
  5. Step 5: Solve for x
    x = 13,225/100
  6. Step 6: Final answer
    x = 132.25

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Why These Related Problems?

These problems maintain the same ratio (1.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.