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Finding the Third Proportional to 15.05 and 21.87

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Solution

The third proportional to 15.05 and 21.87 is: 31.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.05 : 21.87 = 21.87 : x
  2. Step 2: Convert to fraction form
    15.05/21.87 = 21.87/x
  3. Step 3: Cross multiply
    15.05x = 21.87 × 21.87
  4. Step 4: Simplify right side
    15.05x = 478.17
  5. Step 5: Solve for x
    x = 478.17/15.05
  6. Step 6: Final answer
    x = 31.78

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Why These Related Problems?

These problems maintain the same ratio (1.45) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.