Finding the Fourth Proportional to 1,520.80, 2,098.72 and 891.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,520.80 : 2,098.72 = 891.35 : x
2. Step 2: Convert to fraction form
   1,520.80/2,098.72 = 891.35/x
3. Step 3: Cross multiply
   1,520.80x = 2,098.72 × 891.35
4. Step 4: Simplify right side
   1,520.80x = 1,870,681.35
5. Step 5: Solve for x
   x = 1,870,681.35/1,520.80
6. Step 6: Final answer
   x = 1,230.07