Finding the Fourth Proportional to 1,145.28, 1,578.72 and 849.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.28 : 1,578.72 = 849.60 : x
2. Step 2: Convert to fraction form
   1,145.28/1,578.72 = 849.60/x
3. Step 3: Cross multiply
   1,145.28x = 1,578.72 × 849.60
4. Step 4: Simplify right side
   1,145.28x = 1,341,280.51
5. Step 5: Solve for x
   x = 1,341,280.51/1,145.28
6. Step 6: Final answer
   x = 1,171.14