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Finding the Third Proportional to 7.79 and 9.99

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Solution

The third proportional to 7.79 and 9.99 is: 12.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.79 : 9.99 = 9.99 : x
  2. Step 2: Convert to fraction form
    7.79/9.99 = 9.99/x
  3. Step 3: Cross multiply
    7.79x = 9.99 × 9.99
  4. Step 4: Simplify right side
    7.79x = 99.77
  5. Step 5: Solve for x
    x = 99.77/7.79
  6. Step 6: Final answer
    x = 12.81

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Why These Related Problems?

These problems maintain the same ratio (1.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.