Finding the Fourth Proportional to 1,139.96, 1,573.86 and 877.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.96 : 1,573.86 = 877.48 : x
2. Step 2: Convert to fraction form
   1,139.96/1,573.86 = 877.48/x
3. Step 3: Cross multiply
   1,139.96x = 1,573.86 × 877.48
4. Step 4: Simplify right side
   1,139.96x = 1,381,030.67
5. Step 5: Solve for x
   x = 1,381,030.67/1,139.96
6. Step 6: Final answer
   x = 1,211.47