Finding the Fourth Proportional to 1,819.50, 2,510.91 and 991.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,819.50 : 2,510.91 = 991.50 : x
2. Step 2: Convert to fraction form
   1,819.50/2,510.91 = 991.50/x
3. Step 3: Cross multiply
   1,819.50x = 2,510.91 × 991.50
4. Step 4: Simplify right side
   1,819.50x = 2,489,567.27
5. Step 5: Solve for x
   x = 2,489,567.27/1,819.50
6. Step 6: Final answer
   x = 1,368.27