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Finding the Fourth Proportional to 18.80, 25.90 and 15.56

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Solution

The fourth proportional to 18.80, 25.90 and 15.56 is: 21.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.80 : 25.90 = 15.56 : x
  2. Step 2: Convert to fraction form
    18.80/25.90 = 15.56/x
  3. Step 3: Cross multiply
    18.80x = 25.90 × 15.56
  4. Step 4: Simplify right side
    18.80x = 403.00
  5. Step 5: Solve for x
    x = 403.00/18.80
  6. Step 6: Final answer
    x = 21.44

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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.