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Finding the Third Proportional to 31.78 and 72.89

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Solution

The third proportional to 31.78 and 72.89 is: 167.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.78 : 72.89 = 72.89 : x
  2. Step 2: Convert to fraction form
    31.78/72.89 = 72.89/x
  3. Step 3: Cross multiply
    31.78x = 72.89 × 72.89
  4. Step 4: Simplify right side
    31.78x = 5,313.04
  5. Step 5: Solve for x
    x = 5,313.04/31.78
  6. Step 6: Final answer
    x = 167.18

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Why These Related Problems?

These problems maintain the same ratio (2.29) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.