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Finding the Fourth Proportional to 139.09, 208.65 and 70.57

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Solution

The fourth proportional to 139.09, 208.65 and 70.57 is: 105.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.09 : 208.65 = 70.57 : x
  2. Step 2: Convert to fraction form
    139.09/208.65 = 70.57/x
  3. Step 3: Cross multiply
    139.09x = 208.65 × 70.57
  4. Step 4: Simplify right side
    139.09x = 14,723.03
  5. Step 5: Solve for x
    x = 14,723.03/139.09
  6. Step 6: Final answer
    x = 105.85

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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.