Finding the Fourth Proportional to 113.39, 156.56 and 72.01

Step by Step Solution

1. Step 1: Write the proportion equation
   113.39 : 156.56 = 72.01 : x
2. Step 2: Convert to fraction form
   113.39/156.56 = 72.01/x
3. Step 3: Cross multiply
   113.39x = 156.56 × 72.01
4. Step 4: Simplify right side
   113.39x = 11,273.89
5. Step 5: Solve for x
   x = 11,273.89/113.39
6. Step 6: Final answer
   x = 99.43