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Finding the Fourth Proportional to 8.20, 11.31 and 6.65

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Solution

The fourth proportional to 8.20, 11.31 and 6.65 is: 9.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.20 : 11.31 = 6.65 : x
  2. Step 2: Convert to fraction form
    8.20/11.31 = 6.65/x
  3. Step 3: Cross multiply
    8.20x = 11.31 × 6.65
  4. Step 4: Simplify right side
    8.20x = 75.17
  5. Step 5: Solve for x
    x = 75.17/8.20
  6. Step 6: Final answer
    x = 9.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.