Finding the Fourth Proportional to 1,991.31, 2,748.07 and 1,107.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,991.31 : 2,748.07 = 1,107.15 : x
2. Step 2: Convert to fraction form
   1,991.31/2,748.07 = 1,107.15/x
3. Step 3: Cross multiply
   1,991.31x = 2,748.07 × 1,107.15
4. Step 4: Simplify right side
   1,991.31x = 3,042,525.70
5. Step 5: Solve for x
   x = 3,042,525.70/1,991.31
6. Step 6: Final answer
   x = 1,527.90