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Finding the Fourth Proportional to 69.86, 103.89 and 67.70

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Solution

The fourth proportional to 69.86, 103.89 and 67.70 is: 100.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.86 : 103.89 = 67.70 : x
  2. Step 2: Convert to fraction form
    69.86/103.89 = 67.70/x
  3. Step 3: Cross multiply
    69.86x = 103.89 × 67.70
  4. Step 4: Simplify right side
    69.86x = 7,032.50
  5. Step 5: Solve for x
    x = 7,032.50/69.86
  6. Step 6: Final answer
    x = 100.67

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.