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Finding the Fourth Proportional to 12.21, 16.80 and 10.05

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Solution

The fourth proportional to 12.21, 16.80 and 10.05 is: 13.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.21 : 16.80 = 10.05 : x
  2. Step 2: Convert to fraction form
    12.21/16.80 = 10.05/x
  3. Step 3: Cross multiply
    12.21x = 16.80 × 10.05
  4. Step 4: Simplify right side
    12.21x = 168.84
  5. Step 5: Solve for x
    x = 168.84/12.21
  6. Step 6: Final answer
    x = 13.83

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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.