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Finding the Fourth Proportional to 8.20, 12.28 and 8.15

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Solution

The fourth proportional to 8.20, 12.28 and 8.15 is: 12.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.20 : 12.28 = 8.15 : x
  2. Step 2: Convert to fraction form
    8.20/12.28 = 8.15/x
  3. Step 3: Cross multiply
    8.20x = 12.28 × 8.15
  4. Step 4: Simplify right side
    8.20x = 100.08
  5. Step 5: Solve for x
    x = 100.08/8.20
  6. Step 6: Final answer
    x = 12.21

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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.