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Finding the Third Proportional to 155 and 172

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Solution

The third proportional to 155 and 172 is: 190.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    155 : 172 = 172 : x
  2. Step 2: Convert to fraction form
    155/172 = 172/x
  3. Step 3: Cross multiply
    155x = 172 × 172
  4. Step 4: Simplify right side
    155x = 29,584
  5. Step 5: Solve for x
    x = 29,584/155
  6. Step 6: Final answer
    x = 190.86

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Why These Related Problems?

These problems maintain the same ratio (1.11) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.