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Finding the Fourth Proportional to 28.25, 38.90 and 28.16

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Solution

The fourth proportional to 28.25, 38.90 and 28.16 is: 38.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.25 : 38.90 = 28.16 : x
  2. Step 2: Convert to fraction form
    28.25/38.90 = 28.16/x
  3. Step 3: Cross multiply
    28.25x = 38.90 × 28.16
  4. Step 4: Simplify right side
    28.25x = 1,095.42
  5. Step 5: Solve for x
    x = 1,095.42/28.25
  6. Step 6: Final answer
    x = 38.78

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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.