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Finding the Fourth Proportional to 139.57, 209.19 and 105.22

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Solution

The fourth proportional to 139.57, 209.19 and 105.22 is: 157.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.57 : 209.19 = 105.22 : x
  2. Step 2: Convert to fraction form
    139.57/209.19 = 105.22/x
  3. Step 3: Cross multiply
    139.57x = 209.19 × 105.22
  4. Step 4: Simplify right side
    139.57x = 22,009.66
  5. Step 5: Solve for x
    x = 22,009.66/139.57
  6. Step 6: Final answer
    x = 157.70

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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.