Finding the Fourth Proportional to 73.10, 100.91 and 54.78

Step by Step Solution

1. Step 1: Write the proportion equation
   73.10 : 100.91 = 54.78 : x
2. Step 2: Convert to fraction form
   73.10/100.91 = 54.78/x
3. Step 3: Cross multiply
   73.10x = 100.91 × 54.78
4. Step 4: Simplify right side
   73.10x = 5,527.61
5. Step 5: Solve for x
   x = 5,527.61/73.10
6. Step 6: Final answer
   x = 75.61