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Finding the Fourth Proportional to 8.91, 12.31 and 6.19

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Solution

The fourth proportional to 8.91, 12.31 and 6.19 is: 8.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.91 : 12.31 = 6.19 : x
  2. Step 2: Convert to fraction form
    8.91/12.31 = 6.19/x
  3. Step 3: Cross multiply
    8.91x = 12.31 × 6.19
  4. Step 4: Simplify right side
    8.91x = 76.15
  5. Step 5: Solve for x
    x = 76.15/8.91
  6. Step 6: Final answer
    x = 8.55

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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.