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Finding the Fourth Proportional to 28.45, 39.26 and 20.69

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Solution

The fourth proportional to 28.45, 39.26 and 20.69 is: 28.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.45 : 39.26 = 20.69 : x
  2. Step 2: Convert to fraction form
    28.45/39.26 = 20.69/x
  3. Step 3: Cross multiply
    28.45x = 39.26 × 20.69
  4. Step 4: Simplify right side
    28.45x = 812.29
  5. Step 5: Solve for x
    x = 812.29/28.45
  6. Step 6: Final answer
    x = 28.55

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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.