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Finding the Fourth Proportional to 18.87, 28.16 and 18.21

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Solution

The fourth proportional to 18.87, 28.16 and 18.21 is: 27.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.87 : 28.16 = 18.21 : x
  2. Step 2: Convert to fraction form
    18.87/28.16 = 18.21/x
  3. Step 3: Cross multiply
    18.87x = 28.16 × 18.21
  4. Step 4: Simplify right side
    18.87x = 512.86
  5. Step 5: Solve for x
    x = 512.86/18.87
  6. Step 6: Final answer
    x = 27.18

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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.