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Finding the Fourth Proportional to 15.18, 20.88 and 13.65

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Solution

The fourth proportional to 15.18, 20.88 and 13.65 is: 18.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.18 : 20.88 = 13.65 : x
  2. Step 2: Convert to fraction form
    15.18/20.88 = 13.65/x
  3. Step 3: Cross multiply
    15.18x = 20.88 × 13.65
  4. Step 4: Simplify right side
    15.18x = 285.01
  5. Step 5: Solve for x
    x = 285.01/15.18
  6. Step 6: Final answer
    x = 18.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.