Finding the Fourth Proportional to 1,991.90, 2,748.82 and 1,107.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,991.90 : 2,748.82 = 1,107.72 : x
2. Step 2: Convert to fraction form
   1,991.90/2,748.82 = 1,107.72/x
3. Step 3: Cross multiply
   1,991.90x = 2,748.82 × 1,107.72
4. Step 4: Simplify right side
   1,991.90x = 3,044,922.89
5. Step 5: Solve for x
   x = 3,044,922.89/1,991.90
6. Step 6: Final answer
   x = 1,528.65