Finding the Fourth Proportional to 1,200.22, 1,799.88 and 419.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.22 : 1,799.88 = 419.99 : x
2. Step 2: Convert to fraction form
   1,200.22/1,799.88 = 419.99/x
3. Step 3: Cross multiply
   1,200.22x = 1,799.88 × 419.99
4. Step 4: Simplify right side
   1,200.22x = 755,937.39
5. Step 5: Solve for x
   x = 755,937.39/1,200.22
6. Step 6: Final answer
   x = 629.83