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Finding the Fourth Proportional to 42.14, 63.21 and 20.49

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Solution

The fourth proportional to 42.14, 63.21 and 20.49 is: 30.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.14 : 63.21 = 20.49 : x
  2. Step 2: Convert to fraction form
    42.14/63.21 = 20.49/x
  3. Step 3: Cross multiply
    42.14x = 63.21 × 20.49
  4. Step 4: Simplify right side
    42.14x = 1,295.41
  5. Step 5: Solve for x
    x = 1,295.41/42.14
  6. Step 6: Final answer
    x = 30.74

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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.