Finding the Fourth Proportional to 1,100.00, 1,517.92 and 645.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,100.00 : 1,517.92 = 645.90 : x
2. Step 2: Convert to fraction form
   1,100.00/1,517.92 = 645.90/x
3. Step 3: Cross multiply
   1,100.00x = 1,517.92 × 645.90
4. Step 4: Simplify right side
   1,100.00x = 980,422.91
5. Step 5: Solve for x
   x = 980,422.91/1,100.00
6. Step 6: Final answer
   x = 891.30