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Finding the Fourth Proportional to 69.91, 104.91 and 28.80

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Solution

The fourth proportional to 69.91, 104.91 and 28.80 is: 43.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.91 : 104.91 = 28.80 : x
  2. Step 2: Convert to fraction form
    69.91/104.91 = 28.80/x
  3. Step 3: Cross multiply
    69.91x = 104.91 × 28.80
  4. Step 4: Simplify right side
    69.91x = 3,021.41
  5. Step 5: Solve for x
    x = 3,021.41/69.91
  6. Step 6: Final answer
    x = 43.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.