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Finding the Third Proportional to 3.69 and 8.91

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Solution

The third proportional to 3.69 and 8.91 is: 21.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.69 : 8.91 = 8.91 : x
  2. Step 2: Convert to fraction form
    3.69/8.91 = 8.91/x
  3. Step 3: Cross multiply
    3.69x = 8.91 × 8.91
  4. Step 4: Simplify right side
    3.69x = 79.34
  5. Step 5: Solve for x
    x = 79.34/3.69
  6. Step 6: Final answer
    x = 21.47

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Why These Related Problems?

These problems maintain the same ratio (2.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.