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Finding the Fourth Proportional to 13.85, 20.65 and 13.17

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Solution

The fourth proportional to 13.85, 20.65 and 13.17 is: 19.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.85 : 20.65 = 13.17 : x
  2. Step 2: Convert to fraction form
    13.85/20.65 = 13.17/x
  3. Step 3: Cross multiply
    13.85x = 20.65 × 13.17
  4. Step 4: Simplify right side
    13.85x = 271.96
  5. Step 5: Solve for x
    x = 271.96/13.85
  6. Step 6: Final answer
    x = 19.64

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.