Finding the Fourth Proportional to 1,113.86, 1,536.50 and 864.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,113.86 : 1,536.50 = 864.78 : x
2. Step 2: Convert to fraction form
   1,113.86/1,536.50 = 864.78/x
3. Step 3: Cross multiply
   1,113.86x = 1,536.50 × 864.78
4. Step 4: Simplify right side
   1,113.86x = 1,328,734.47
5. Step 5: Solve for x
   x = 1,328,734.47/1,113.86
6. Step 6: Final answer
   x = 1,192.91