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Finding the Fourth Proportional to 28.72, 42.84 and 28.12

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Solution

The fourth proportional to 28.72, 42.84 and 28.12 is: 41.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.72 : 42.84 = 28.12 : x
  2. Step 2: Convert to fraction form
    28.72/42.84 = 28.12/x
  3. Step 3: Cross multiply
    28.72x = 42.84 × 28.12
  4. Step 4: Simplify right side
    28.72x = 1,204.66
  5. Step 5: Solve for x
    x = 1,204.66/28.72
  6. Step 6: Final answer
    x = 41.95

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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.