Finding the Fourth Proportional to 1,422.15, 1,961.86 and 1,225.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.15 : 1,961.86 = 1,225.32 : x
2. Step 2: Convert to fraction form
   1,422.15/1,961.86 = 1,225.32/x
3. Step 3: Cross multiply
   1,422.15x = 1,961.86 × 1,225.32
4. Step 4: Simplify right side
   1,422.15x = 2,403,906.30
5. Step 5: Solve for x
   x = 2,403,906.30/1,422.15
6. Step 6: Final answer
   x = 1,690.33