Finding the Fourth Proportional to 1,328.00, 1,991.39 and 890.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,328.00 : 1,991.39 = 890.60 : x
2. Step 2: Convert to fraction form
   1,328.00/1,991.39 = 890.60/x
3. Step 3: Cross multiply
   1,328.00x = 1,991.39 × 890.60
4. Step 4: Simplify right side
   1,328.00x = 1,773,517.52
5. Step 5: Solve for x
   x = 1,773,517.52/1,328.00
6. Step 6: Final answer
   x = 1,335.49