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Finding the Fourth Proportional to 69.14, 103.71 and 21.05

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Solution

The fourth proportional to 69.14, 103.71 and 21.05 is: 31.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.14 : 103.71 = 21.05 : x
  2. Step 2: Convert to fraction form
    69.14/103.71 = 21.05/x
  3. Step 3: Cross multiply
    69.14x = 103.71 × 21.05
  4. Step 4: Simplify right side
    69.14x = 2,183.04
  5. Step 5: Solve for x
    x = 2,183.04/69.14
  6. Step 6: Final answer
    x = 31.57

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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.