Finding the Fourth Proportional to 1,114.84, 1,669.42 and 931.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,114.84 : 1,669.42 = 931.78 : x
2. Step 2: Convert to fraction form
   1,114.84/1,669.42 = 931.78/x
3. Step 3: Cross multiply
   1,114.84x = 1,669.42 × 931.78
4. Step 4: Simplify right side
   1,114.84x = 1,555,532.17
5. Step 5: Solve for x
   x = 1,555,532.17/1,114.84
6. Step 6: Final answer
   x = 1,395.30