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Finding the Third Proportional to 7.21 and 11.20

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Solution

The third proportional to 7.21 and 11.20 is: 17.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.21 : 11.20 = 11.20 : x
  2. Step 2: Convert to fraction form
    7.21/11.20 = 11.20/x
  3. Step 3: Cross multiply
    7.21x = 11.20 × 11.20
  4. Step 4: Simplify right side
    7.21x = 125.38
  5. Step 5: Solve for x
    x = 125.38/7.21
  6. Step 6: Final answer
    x = 17.40

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Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.