Finding the Fourth Proportional to 1,790.19, 2,471.78 and 1,578.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,790.19 : 2,471.78 = 1,578.78 : x
2. Step 2: Convert to fraction form
   1,790.19/2,471.78 = 1,578.78/x
3. Step 3: Cross multiply
   1,790.19x = 2,471.78 × 1,578.78
4. Step 4: Simplify right side
   1,790.19x = 3,902,400.78
5. Step 5: Solve for x
   x = 3,902,400.78/1,790.19
6. Step 6: Final answer
   x = 2,179.88