Finding the Fourth Proportional to 93.39, 128.86 and 56.55

Step by Step Solution

1. Step 1: Write the proportion equation
   93.39 : 128.86 = 56.55 : x
2. Step 2: Convert to fraction form
   93.39/128.86 = 56.55/x
3. Step 3: Cross multiply
   93.39x = 128.86 × 56.55
4. Step 4: Simplify right side
   93.39x = 7,287.10
5. Step 5: Solve for x
   x = 7,287.10/93.39
6. Step 6: Final answer
   x = 78.03