Finding the Third Proportional to 42,121.50 and 90,991.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,121.50 : 90,991.50 = 90,991.50 : x
2. Step 2: Convert to fraction form
   42,121.50/90,991.50 = 90,991.50/x
3. Step 3: Cross multiply
   42,121.50x = 90,991.50 × 90,991.50
4. Step 4: Simplify right side
   42,121.50x = 8,279,453,072.25
5. Step 5: Solve for x
   x = 8,279,453,072.25/42,121.50
6. Step 6: Final answer
   x = 196,561.21