Finding the Fourth Proportional to 78.30, 107.99 and 55.02

Step by Step Solution

1. Step 1: Write the proportion equation
   78.30 : 107.99 = 55.02 : x
2. Step 2: Convert to fraction form
   78.30/107.99 = 55.02/x
3. Step 3: Cross multiply
   78.30x = 107.99 × 55.02
4. Step 4: Simplify right side
   78.30x = 5,941.33
5. Step 5: Solve for x
   x = 5,941.33/78.30
6. Step 6: Final answer
   x = 75.88