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Finding the Fourth Proportional to 27.28, 40.78 and 20.86

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Solution

The fourth proportional to 27.28, 40.78 and 20.86 is: 31.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.28 : 40.78 = 20.86 : x
  2. Step 2: Convert to fraction form
    27.28/40.78 = 20.86/x
  3. Step 3: Cross multiply
    27.28x = 40.78 × 20.86
  4. Step 4: Simplify right side
    27.28x = 850.67
  5. Step 5: Solve for x
    x = 850.67/27.28
  6. Step 6: Final answer
    x = 31.18

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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.