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Finding the Fourth Proportional to 20.76, 30.98 and 20.05

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Solution

The fourth proportional to 20.76, 30.98 and 20.05 is: 29.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.76 : 30.98 = 20.05 : x
  2. Step 2: Convert to fraction form
    20.76/30.98 = 20.05/x
  3. Step 3: Cross multiply
    20.76x = 30.98 × 20.05
  4. Step 4: Simplify right side
    20.76x = 621.12
  5. Step 5: Solve for x
    x = 621.12/20.76
  6. Step 6: Final answer
    x = 29.92

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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.