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Finding the Fourth Proportional to 13.80, 20.72 and 13.68

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Solution

The fourth proportional to 13.80, 20.72 and 13.68 is: 20.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.80 : 20.72 = 13.68 : x
  2. Step 2: Convert to fraction form
    13.80/20.72 = 13.68/x
  3. Step 3: Cross multiply
    13.80x = 20.72 × 13.68
  4. Step 4: Simplify right side
    13.80x = 283.45
  5. Step 5: Solve for x
    x = 283.45/13.80
  6. Step 6: Final answer
    x = 20.54

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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.