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Finding the Fourth Proportional to 15.09, 20.80 and 11.59

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Solution

The fourth proportional to 15.09, 20.80 and 11.59 is: 15.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.09 : 20.80 = 11.59 : x
  2. Step 2: Convert to fraction form
    15.09/20.80 = 11.59/x
  3. Step 3: Cross multiply
    15.09x = 20.80 × 11.59
  4. Step 4: Simplify right side
    15.09x = 241.03
  5. Step 5: Solve for x
    x = 241.03/15.09
  6. Step 6: Final answer
    x = 15.98

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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.