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Finding the Fourth Proportional to 28.78, 43.14 and 28.09

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Solution

The fourth proportional to 28.78, 43.14 and 28.09 is: 42.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.78 : 43.14 = 28.09 : x
  2. Step 2: Convert to fraction form
    28.78/43.14 = 28.09/x
  3. Step 3: Cross multiply
    28.78x = 43.14 × 28.09
  4. Step 4: Simplify right side
    28.78x = 1,211.80
  5. Step 5: Solve for x
    x = 1,211.80/28.78
  6. Step 6: Final answer
    x = 42.11

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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.