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Finding the Fourth Proportional to 18.80, 28.18 and 15.61

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Solution

The fourth proportional to 18.80, 28.18 and 15.61 is: 23.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.80 : 28.18 = 15.61 : x
  2. Step 2: Convert to fraction form
    18.80/28.18 = 15.61/x
  3. Step 3: Cross multiply
    18.80x = 28.18 × 15.61
  4. Step 4: Simplify right side
    18.80x = 439.89
  5. Step 5: Solve for x
    x = 439.89/18.80
  6. Step 6: Final answer
    x = 23.40

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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.