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Finding the Fourth Proportional to 20.45, 28.18 and 19.65

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Solution

The fourth proportional to 20.45, 28.18 and 19.65 is: 27.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.45 : 28.18 = 19.65 : x
  2. Step 2: Convert to fraction form
    20.45/28.18 = 19.65/x
  3. Step 3: Cross multiply
    20.45x = 28.18 × 19.65
  4. Step 4: Simplify right side
    20.45x = 553.87
  5. Step 5: Solve for x
    x = 553.87/20.45
  6. Step 6: Final answer
    x = 27.08

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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.