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Finding the Fourth Proportional to 8.91, 12.31 and 7.47

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Solution

The fourth proportional to 8.91, 12.31 and 7.47 is: 10.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.91 : 12.31 = 7.47 : x
  2. Step 2: Convert to fraction form
    8.91/12.31 = 7.47/x
  3. Step 3: Cross multiply
    8.91x = 12.31 × 7.47
  4. Step 4: Simplify right side
    8.91x = 91.96
  5. Step 5: Solve for x
    x = 91.96/8.91
  6. Step 6: Final answer
    x = 10.32

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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.