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Finding the Fourth Proportional to 13.71, 20.56 and 8.91

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Solution

The fourth proportional to 13.71, 20.56 and 8.91 is: 13.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.71 : 20.56 = 8.91 : x
  2. Step 2: Convert to fraction form
    13.71/20.56 = 8.91/x
  3. Step 3: Cross multiply
    13.71x = 20.56 × 8.91
  4. Step 4: Simplify right side
    13.71x = 183.19
  5. Step 5: Solve for x
    x = 183.19/13.71
  6. Step 6: Final answer
    x = 13.36

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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.