Finding the Fourth Proportional to 112.79, 155.50 and 86.25

Step by Step Solution

1. Step 1: Write the proportion equation
   112.79 : 155.50 = 86.25 : x
2. Step 2: Convert to fraction form
   112.79/155.50 = 86.25/x
3. Step 3: Cross multiply
   112.79x = 155.50 × 86.25
4. Step 4: Simplify right side
   112.79x = 13,410.67
5. Step 5: Solve for x
   x = 13,410.67/112.79
6. Step 6: Final answer
   x = 118.90