Finding the Fourth Proportional to 105.30, 157.55 and 78.37

Step by Step Solution

1. Step 1: Write the proportion equation
   105.30 : 157.55 = 78.37 : x
2. Step 2: Convert to fraction form
   105.30/157.55 = 78.37/x
3. Step 3: Cross multiply
   105.30x = 157.55 × 78.37
4. Step 4: Simplify right side
   105.30x = 12,346.41
5. Step 5: Solve for x
   x = 12,346.41/105.30
6. Step 6: Final answer
   x = 117.25