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Finding the Third Proportional to 3.90 and 8.54

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Solution

The third proportional to 3.90 and 8.54 is: 18.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.90 : 8.54 = 8.54 : x
  2. Step 2: Convert to fraction form
    3.90/8.54 = 8.54/x
  3. Step 3: Cross multiply
    3.90x = 8.54 × 8.54
  4. Step 4: Simplify right side
    3.90x = 72.98
  5. Step 5: Solve for x
    x = 72.98/3.90
  6. Step 6: Final answer
    x = 18.70

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Why These Related Problems?

These problems maintain the same ratio (2.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.