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Finding the Fourth Proportional to 9.31, 13.90 and 8.18

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Solution

The fourth proportional to 9.31, 13.90 and 8.18 is: 12.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.31 : 13.90 = 8.18 : x
  2. Step 2: Convert to fraction form
    9.31/13.90 = 8.18/x
  3. Step 3: Cross multiply
    9.31x = 13.90 × 8.18
  4. Step 4: Simplify right side
    9.31x = 113.70
  5. Step 5: Solve for x
    x = 113.70/9.31
  6. Step 6: Final answer
    x = 12.21

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.