Finding the Fourth Proportional to 1,422.54, 1,964.25 and 1,290.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.54 : 1,964.25 = 1,290.78 : x
2. Step 2: Convert to fraction form
   1,422.54/1,964.25 = 1,290.78/x
3. Step 3: Cross multiply
   1,422.54x = 1,964.25 × 1,290.78
4. Step 4: Simplify right side
   1,422.54x = 2,535,414.62
5. Step 5: Solve for x
   x = 2,535,414.62/1,422.54
6. Step 6: Final answer
   x = 1,782.32