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Finding the Fourth Proportional to 15.21, 20.97 and 12.51

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Solution

The fourth proportional to 15.21, 20.97 and 12.51 is: 17.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.21 : 20.97 = 12.51 : x
  2. Step 2: Convert to fraction form
    15.21/20.97 = 12.51/x
  3. Step 3: Cross multiply
    15.21x = 20.97 × 12.51
  4. Step 4: Simplify right side
    15.21x = 262.33
  5. Step 5: Solve for x
    x = 262.33/15.21
  6. Step 6: Final answer
    x = 17.25

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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.