Finding the Fourth Proportional to 99.50, 137.23 and 78.50

Step by Step Solution

1. Step 1: Write the proportion equation
   99.50 : 137.23 = 78.50 : x
2. Step 2: Convert to fraction form
   99.50/137.23 = 78.50/x
3. Step 3: Cross multiply
   99.50x = 137.23 × 78.50
4. Step 4: Simplify right side
   99.50x = 10,772.56
5. Step 5: Solve for x
   x = 10,772.56/99.50
6. Step 6: Final answer
   x = 108.27