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Finding the Third Proportional to 5.20 and 9.91

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Solution

The third proportional to 5.20 and 9.91 is: 18.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.20 : 9.91 = 9.91 : x
  2. Step 2: Convert to fraction form
    5.20/9.91 = 9.91/x
  3. Step 3: Cross multiply
    5.20x = 9.91 × 9.91
  4. Step 4: Simplify right side
    5.20x = 98.29
  5. Step 5: Solve for x
    x = 98.29/5.20
  6. Step 6: Final answer
    x = 18.89

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Why These Related Problems?

These problems maintain the same ratio (1.91) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.