Finding the Fourth Proportional to 1,196.48, 1,793.64 and 426.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,196.48 : 1,793.64 = 426.80 : x
2. Step 2: Convert to fraction form
   1,196.48/1,793.64 = 426.80/x
3. Step 3: Cross multiply
   1,196.48x = 1,793.64 × 426.80
4. Step 4: Simplify right side
   1,196.48x = 765,525.55
5. Step 5: Solve for x
   x = 765,525.55/1,196.48
6. Step 6: Final answer
   x = 639.81