Finding the Third Proportional to 78,621 and 111,136.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,621 : 111,136.50 = 111,136.50 : x
2. Step 2: Convert to fraction form
   78,621/111,136.50 = 111,136.50/x
3. Step 3: Cross multiply
   78,621x = 111,136.50 × 111,136.50
4. Step 4: Simplify right side
   78,621x = 12,351,321,632.25
5. Step 5: Solve for x
   x = 12,351,321,632.25/78,621
6. Step 6: Final answer
   x = 157,099.52