Finding the Fourth Proportional to 72.39, 109.16 and 71.58

Step by Step Solution

1. Step 1: Write the proportion equation
   72.39 : 109.16 = 71.58 : x
2. Step 2: Convert to fraction form
   72.39/109.16 = 71.58/x
3. Step 3: Cross multiply
   72.39x = 109.16 × 71.58
4. Step 4: Simplify right side
   72.39x = 7,813.31
5. Step 5: Solve for x
   x = 7,813.31/72.39
6. Step 6: Final answer
   x = 107.93