Finding the Fourth Proportional to 1,390.77, 2,088.27 and 873.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.77 : 2,088.27 = 873.99 : x
2. Step 2: Convert to fraction form
   1,390.77/2,088.27 = 873.99/x
3. Step 3: Cross multiply
   1,390.77x = 2,088.27 × 873.99
4. Step 4: Simplify right side
   1,390.77x = 1,825,127.10
5. Step 5: Solve for x
   x = 1,825,127.10/1,390.77
6. Step 6: Final answer
   x = 1,312.31