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Finding the Fourth Proportional to 13.55, 20.28 and 9.91

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Solution

The fourth proportional to 13.55, 20.28 and 9.91 is: 14.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.55 : 20.28 = 9.91 : x
  2. Step 2: Convert to fraction form
    13.55/20.28 = 9.91/x
  3. Step 3: Cross multiply
    13.55x = 20.28 × 9.91
  4. Step 4: Simplify right side
    13.55x = 200.93
  5. Step 5: Solve for x
    x = 200.93/13.55
  6. Step 6: Final answer
    x = 14.82

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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.