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Finding the Fourth Proportional to 13.51, 18.65 and 12.21

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Solution

The fourth proportional to 13.51, 18.65 and 12.21 is: 16.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.51 : 18.65 = 12.21 : x
  2. Step 2: Convert to fraction form
    13.51/18.65 = 12.21/x
  3. Step 3: Cross multiply
    13.51x = 18.65 × 12.21
  4. Step 4: Simplify right side
    13.51x = 227.72
  5. Step 5: Solve for x
    x = 227.72/13.51
  6. Step 6: Final answer
    x = 16.86

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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.