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Finding the Fourth Proportional to 8.10, 12.15 and 2.09

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Solution

The fourth proportional to 8.10, 12.15 and 2.09 is: 3.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.10 : 12.15 = 2.09 : x
  2. Step 2: Convert to fraction form
    8.10/12.15 = 2.09/x
  3. Step 3: Cross multiply
    8.10x = 12.15 × 2.09
  4. Step 4: Simplify right side
    8.10x = 25.35
  5. Step 5: Solve for x
    x = 25.35/8.10
  6. Step 6: Final answer
    x = 3.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.