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Finding the Fourth Proportional to 15.19, 20.86 and 13.80

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Solution

The fourth proportional to 15.19, 20.86 and 13.80 is: 18.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.19 : 20.86 = 13.80 : x
  2. Step 2: Convert to fraction form
    15.19/20.86 = 13.80/x
  3. Step 3: Cross multiply
    15.19x = 20.86 × 13.80
  4. Step 4: Simplify right side
    15.19x = 287.91
  5. Step 5: Solve for x
    x = 287.91/15.19
  6. Step 6: Final answer
    x = 18.96

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.