Finding the Fourth Proportional to 93.30, 128.73 and 78.61

Step by Step Solution

1. Step 1: Write the proportion equation
   93.30 : 128.73 = 78.61 : x
2. Step 2: Convert to fraction form
   93.30/128.73 = 78.61/x
3. Step 3: Cross multiply
   93.30x = 128.73 × 78.61
4. Step 4: Simplify right side
   93.30x = 10,119.02
5. Step 5: Solve for x
   x = 10,119.02/93.30
6. Step 6: Final answer
   x = 108.46