Finding the Fourth Proportional to 666,111.99, 919,179.01 and 375,707.55

Step by Step Solution

1. Step 1: Write the proportion equation
   666,111.99 : 919,179.01 = 375,707.55 : x
2. Step 2: Convert to fraction form
   666,111.99/919,179.01 = 375,707.55/x
3. Step 3: Cross multiply
   666,111.99x = 919,179.01 × 375,707.55
4. Step 4: Simplify right side
   666,111.99x = 345,342,493,858.53
5. Step 5: Solve for x
   x = 345,342,493,858.53/666,111.99
6. Step 6: Final answer
   x = 518,445.09