Finding the Fourth Proportional to 78,728.58, 117,987.12 and 43,136.37

Step by Step Solution

1. Step 1: Write the proportion equation
   78,728.58 : 117,987.12 = 43,136.37 : x
2. Step 2: Convert to fraction form
   78,728.58/117,987.12 = 43,136.37/x
3. Step 3: Cross multiply
   78,728.58x = 117,987.12 × 43,136.37
4. Step 4: Simplify right side
   78,728.58x = 5,089,536,063.55
5. Step 5: Solve for x
   x = 5,089,536,063.55/78,728.58
6. Step 6: Final answer
   x = 64,646.61