Finding the Fourth Proportional to 1,079.10, 1,485.72 and 912.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.10 : 1,485.72 = 912.96 : x
2. Step 2: Convert to fraction form
   1,079.10/1,485.72 = 912.96/x
3. Step 3: Cross multiply
   1,079.10x = 1,485.72 × 912.96
4. Step 4: Simplify right side
   1,079.10x = 1,356,402.93
5. Step 5: Solve for x
   x = 1,356,402.93/1,079.10
6. Step 6: Final answer
   x = 1,256.98