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Finding the Third Proportional to 1.21 and 3.11

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Solution

The third proportional to 1.21 and 3.11 is: 7.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1.21 : 3.11 = 3.11 : x
  2. Step 2: Convert to fraction form
    1.21/3.11 = 3.11/x
  3. Step 3: Cross multiply
    1.21x = 3.11 × 3.11
  4. Step 4: Simplify right side
    1.21x = 9.69
  5. Step 5: Solve for x
    x = 9.69/1.21
  6. Step 6: Final answer
    x = 7.99

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Why These Related Problems?

These problems maintain the same ratio (2.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.