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Finding the Third Proportional to 8.70 and 13.21

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Solution

The third proportional to 8.70 and 13.21 is: 20.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.70 : 13.21 = 13.21 : x
  2. Step 2: Convert to fraction form
    8.70/13.21 = 13.21/x
  3. Step 3: Cross multiply
    8.70x = 13.21 × 13.21
  4. Step 4: Simplify right side
    8.70x = 174.50
  5. Step 5: Solve for x
    x = 174.50/8.70
  6. Step 6: Final answer
    x = 20.06

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Why These Related Problems?

These problems maintain the same ratio (1.52) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.