Finding the Fourth Proportional to 1,131.15, 1,561.06 and 633.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.15 : 1,561.06 = 633.78 : x
2. Step 2: Convert to fraction form
   1,131.15/1,561.06 = 633.78/x
3. Step 3: Cross multiply
   1,131.15x = 1,561.06 × 633.78
4. Step 4: Simplify right side
   1,131.15x = 989,360.80
5. Step 5: Solve for x
   x = 989,360.80/1,131.15
6. Step 6: Final answer
   x = 874.65