Finding the Fourth Proportional to 1,189,505.12, 1,641,518.72 and 645,641.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189,505.12 : 1,641,518.72 = 645,641.02 : x
2. Step 2: Convert to fraction form
   1,189,505.12/1,641,518.72 = 645,641.02/x
3. Step 3: Cross multiply
   1,189,505.12x = 1,641,518.72 × 645,641.02
4. Step 4: Simplify right side
   1,189,505.12x = 1,059,831,820,729.89
5. Step 5: Solve for x
   x = 1,059,831,820,729.89/1,189,505.12
6. Step 6: Final answer
   x = 890,985.51