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Finding the Third Proportional to 72 and 80

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Solution

The third proportional to 72 and 80 is: 88.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    72 : 80 = 80 : x
  2. Step 2: Convert to fraction form
    72/80 = 80/x
  3. Step 3: Cross multiply
    72x = 80 × 80
  4. Step 4: Simplify right side
    72x = 6,400
  5. Step 5: Solve for x
    x = 6,400/72
  6. Step 6: Final answer
    x = 88.89

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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.