Finding the Fourth Proportional to 1,991.86, 2,748.78 and 1,107.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,991.86 : 2,748.78 = 1,107.76 : x
2. Step 2: Convert to fraction form
   1,991.86/2,748.78 = 1,107.76/x
3. Step 3: Cross multiply
   1,991.86x = 2,748.78 × 1,107.76
4. Step 4: Simplify right side
   1,991.86x = 3,044,988.53
5. Step 5: Solve for x
   x = 3,044,988.53/1,991.86
6. Step 6: Final answer
   x = 1,528.72