Finding the Fourth Proportional to 72.05, 107.38 and 70.69

Step by Step Solution

1. Step 1: Write the proportion equation
   72.05 : 107.38 = 70.69 : x
2. Step 2: Convert to fraction form
   72.05/107.38 = 70.69/x
3. Step 3: Cross multiply
   72.05x = 107.38 × 70.69
4. Step 4: Simplify right side
   72.05x = 7,590.69
5. Step 5: Solve for x
   x = 7,590.69/72.05
6. Step 6: Final answer
   x = 105.35