Finding the Fourth Proportional to 1,128,478.94, 1,557,300.69 and 645,054.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128,478.94 : 1,557,300.69 = 645,054.50 : x
2. Step 2: Convert to fraction form
   1,128,478.94/1,557,300.69 = 645,054.50/x
3. Step 3: Cross multiply
   1,128,478.94x = 1,557,300.69 × 645,054.50
4. Step 4: Simplify right side
   1,128,478.94x = 1,004,543,813,071.04
5. Step 5: Solve for x
   x = 1,004,543,813,071.04/1,128,478.94
6. Step 6: Final answer
   x = 890,175.06