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Finding the Third Proportional to 15.56 and 21.80

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Solution

The third proportional to 15.56 and 21.80 is: 30.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.56 : 21.80 = 21.80 : x
  2. Step 2: Convert to fraction form
    15.56/21.80 = 21.80/x
  3. Step 3: Cross multiply
    15.56x = 21.80 × 21.80
  4. Step 4: Simplify right side
    15.56x = 475.10
  5. Step 5: Solve for x
    x = 475.10/15.56
  6. Step 6: Final answer
    x = 30.53

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.