Finding the Fourth Proportional to 93.31, 128.78 and 54.50

Step by Step Solution

1. Step 1: Write the proportion equation
   93.31 : 128.78 = 54.50 : x
2. Step 2: Convert to fraction form
   93.31/128.78 = 54.50/x
3. Step 3: Cross multiply
   93.31x = 128.78 × 54.50
4. Step 4: Simplify right side
   93.31x = 7,018.51
5. Step 5: Solve for x
   x = 7,018.51/93.31
6. Step 6: Final answer
   x = 75.22