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Finding the Fourth Proportional to 20.34, 30.48 and 8.31

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Solution

The fourth proportional to 20.34, 30.48 and 8.31 is: 12.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.34 : 30.48 = 8.31 : x
  2. Step 2: Convert to fraction form
    20.34/30.48 = 8.31/x
  3. Step 3: Cross multiply
    20.34x = 30.48 × 8.31
  4. Step 4: Simplify right side
    20.34x = 253.09
  5. Step 5: Solve for x
    x = 253.09/20.34
  6. Step 6: Final answer
    x = 12.45

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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.