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Finding the Third Proportional to 7 and 9

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Solution

The third proportional to 7 and 9 is: 11.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    7 : 9 = 9 : x
  2. Step 2: Convert to fraction form
    7/9 = 9/x
  3. Step 3: Cross multiply
    7x = 9 × 9
  4. Step 4: Simplify right side
    7x = 81
  5. Step 5: Solve for x
    x = 81/7
  6. Step 6: Final answer
    x = 11.57

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Why These Related Problems?

These problems maintain the same ratio (1.29) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.