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Finding the Third Proportional to 18 and 19

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Solution

The third proportional to 18 and 19 is: 20.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    18 : 19 = 19 : x
  2. Step 2: Convert to fraction form
    18/19 = 19/x
  3. Step 3: Cross multiply
    18x = 19 × 19
  4. Step 4: Simplify right side
    18x = 361
  5. Step 5: Solve for x
    x = 361/18
  6. Step 6: Final answer
    x = 20.06

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Double scale
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Similar ratio
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.06) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.