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Finding the Fourth Proportional to 15.09, 20.82 and 13.55

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Solution

The fourth proportional to 15.09, 20.82 and 13.55 is: 18.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.09 : 20.82 = 13.55 : x
  2. Step 2: Convert to fraction form
    15.09/20.82 = 13.55/x
  3. Step 3: Cross multiply
    15.09x = 20.82 × 13.55
  4. Step 4: Simplify right side
    15.09x = 282.11
  5. Step 5: Solve for x
    x = 282.11/15.09
  6. Step 6: Final answer
    x = 18.70

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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.