Finding the Fourth Proportional to 1,991.60, 2,748.42 and 1,107.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,991.60 : 2,748.42 = 1,107.42 : x
2. Step 2: Convert to fraction form
   1,991.60/2,748.42 = 1,107.42/x
3. Step 3: Cross multiply
   1,991.60x = 2,748.42 × 1,107.42
4. Step 4: Simplify right side
   1,991.60x = 3,043,655.28
5. Step 5: Solve for x
   x = 3,043,655.28/1,991.60
6. Step 6: Final answer
   x = 1,528.25