Finding the Fourth Proportional to 1,399.28, 1,931.78 and 876.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.28 : 1,931.78 = 876.02 : x
2. Step 2: Convert to fraction form
   1,399.28/1,931.78 = 876.02/x
3. Step 3: Cross multiply
   1,399.28x = 1,931.78 × 876.02
4. Step 4: Simplify right side
   1,399.28x = 1,692,270.45
5. Step 5: Solve for x
   x = 1,692,270.45/1,399.28
6. Step 6: Final answer
   x = 1,209.39