Finding the Fourth Proportional to 2,379.80, 3,570.72 and 919.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,379.80 : 3,570.72 = 919.98 : x
2. Step 2: Convert to fraction form
   2,379.80/3,570.72 = 919.98/x
3. Step 3: Cross multiply
   2,379.80x = 3,570.72 × 919.98
4. Step 4: Simplify right side
   2,379.80x = 3,284,990.99
5. Step 5: Solve for x
   x = 3,284,990.99/2,379.80
6. Step 6: Final answer
   x = 1,380.36