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Finding the Fourth Proportional to 28.14, 38.78 and 21.98

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Solution

The fourth proportional to 28.14, 38.78 and 21.98 is: 30.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.14 : 38.78 = 21.98 : x
  2. Step 2: Convert to fraction form
    28.14/38.78 = 21.98/x
  3. Step 3: Cross multiply
    28.14x = 38.78 × 21.98
  4. Step 4: Simplify right side
    28.14x = 852.38
  5. Step 5: Solve for x
    x = 852.38/28.14
  6. Step 6: Final answer
    x = 30.29

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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.