Finding the Fourth Proportional to 113.59, 156.72 and 64.47

Step by Step Solution

1. Step 1: Write the proportion equation
   113.59 : 156.72 = 64.47 : x
2. Step 2: Convert to fraction form
   113.59/156.72 = 64.47/x
3. Step 3: Cross multiply
   113.59x = 156.72 × 64.47
4. Step 4: Simplify right side
   113.59x = 10,103.51
5. Step 5: Solve for x
   x = 10,103.51/113.59
6. Step 6: Final answer
   x = 88.95