Finding the Fourth Proportional to 118.03, 162.61 and 78.61

Step by Step Solution

1. Step 1: Write the proportion equation
   118.03 : 162.61 = 78.61 : x
2. Step 2: Convert to fraction form
   118.03/162.61 = 78.61/x
3. Step 3: Cross multiply
   118.03x = 162.61 × 78.61
4. Step 4: Simplify right side
   118.03x = 12,782.77
5. Step 5: Solve for x
   x = 12,782.77/118.03
6. Step 6: Final answer
   x = 108.31