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Finding the Fourth Proportional to 139.36, 208.96 and 70.85

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Solution

The fourth proportional to 139.36, 208.96 and 70.85 is: 106.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.36 : 208.96 = 70.85 : x
  2. Step 2: Convert to fraction form
    139.36/208.96 = 70.85/x
  3. Step 3: Cross multiply
    139.36x = 208.96 × 70.85
  4. Step 4: Simplify right side
    139.36x = 14,804.82
  5. Step 5: Solve for x
    x = 14,804.82/139.36
  6. Step 6: Final answer
    x = 106.23

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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.