Finding the Fourth Proportional to 99.55, 137.54 and 77.50

Step by Step Solution

1. Step 1: Write the proportion equation
   99.55 : 137.54 = 77.50 : x
2. Step 2: Convert to fraction form
   99.55/137.54 = 77.50/x
3. Step 3: Cross multiply
   99.55x = 137.54 × 77.50
4. Step 4: Simplify right side
   99.55x = 10,658.27
5. Step 5: Solve for x
   x = 10,658.27/99.55
6. Step 6: Final answer
   x = 107.07