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Finding the Fourth Proportional to 28.56, 39.15 and 28.29

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Solution

The fourth proportional to 28.56, 39.15 and 28.29 is: 38.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.56 : 39.15 = 28.29 : x
  2. Step 2: Convert to fraction form
    28.56/39.15 = 28.29/x
  3. Step 3: Cross multiply
    28.56x = 39.15 × 28.29
  4. Step 4: Simplify right side
    28.56x = 1,107.55
  5. Step 5: Solve for x
    x = 1,107.55/28.56
  6. Step 6: Final answer
    x = 38.78

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.