Finding the Fourth Proportional to 119.60, 164.91 and 78.15

Step by Step Solution

1. Step 1: Write the proportion equation
   119.60 : 164.91 = 78.15 : x
2. Step 2: Convert to fraction form
   119.60/164.91 = 78.15/x
3. Step 3: Cross multiply
   119.60x = 164.91 × 78.15
4. Step 4: Simplify right side
   119.60x = 12,887.72
5. Step 5: Solve for x
   x = 12,887.72/119.60
6. Step 6: Final answer
   x = 107.76