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Finding the Fourth Proportional to 27.65, 38.16 and 20.39

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Solution

The fourth proportional to 27.65, 38.16 and 20.39 is: 28.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.65 : 38.16 = 20.39 : x
  2. Step 2: Convert to fraction form
    27.65/38.16 = 20.39/x
  3. Step 3: Cross multiply
    27.65x = 38.16 × 20.39
  4. Step 4: Simplify right side
    27.65x = 778.18
  5. Step 5: Solve for x
    x = 778.18/27.65
  6. Step 6: Final answer
    x = 28.14

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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.