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Finding the Fourth Proportional to 20.91, 28.79 and 19.55

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Solution

The fourth proportional to 20.91, 28.79 and 19.55 is: 26.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.91 : 28.79 = 19.55 : x
  2. Step 2: Convert to fraction form
    20.91/28.79 = 19.55/x
  3. Step 3: Cross multiply
    20.91x = 28.79 × 19.55
  4. Step 4: Simplify right side
    20.91x = 562.82
  5. Step 5: Solve for x
    x = 562.82/20.91
  6. Step 6: Final answer
    x = 26.92

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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.