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Finding the Fourth Proportional to 70.72, 105.84 and 69.70

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Solution

The fourth proportional to 70.72, 105.84 and 69.70 is: 104.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.72 : 105.84 = 69.70 : x
  2. Step 2: Convert to fraction form
    70.72/105.84 = 69.70/x
  3. Step 3: Cross multiply
    70.72x = 105.84 × 69.70
  4. Step 4: Simplify right side
    70.72x = 7,377.05
  5. Step 5: Solve for x
    x = 7,377.05/70.72
  6. Step 6: Final answer
    x = 104.31

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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.