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Finding the Third Proportional to 18.75 and 20.25

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Solution

The third proportional to 18.75 and 20.25 is: 21.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.75 : 20.25 = 20.25 : x
  2. Step 2: Convert to fraction form
    18.75/20.25 = 20.25/x
  3. Step 3: Cross multiply
    18.75x = 20.25 × 20.25
  4. Step 4: Simplify right side
    18.75x = 410.06
  5. Step 5: Solve for x
    x = 410.06/18.75
  6. Step 6: Final answer
    x = 21.87

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Why These Related Problems?

These problems maintain the same ratio (1.08) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.