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Finding the Fourth Proportional to 20.84, 31.20 and 18.95

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Solution

The fourth proportional to 20.84, 31.20 and 18.95 is: 28.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.84 : 31.20 = 18.95 : x
  2. Step 2: Convert to fraction form
    20.84/31.20 = 18.95/x
  3. Step 3: Cross multiply
    20.84x = 31.20 × 18.95
  4. Step 4: Simplify right side
    20.84x = 591.24
  5. Step 5: Solve for x
    x = 591.24/20.84
  6. Step 6: Final answer
    x = 28.37

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.