Finding the Fourth Proportional to 1,131.77, 1,561.77 and 634.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.77 : 1,561.77 = 634.31 : x
2. Step 2: Convert to fraction form
   1,131.77/1,561.77 = 634.31/x
3. Step 3: Cross multiply
   1,131.77x = 1,561.77 × 634.31
4. Step 4: Simplify right side
   1,131.77x = 990,650.23
5. Step 5: Solve for x
   x = 990,650.23/1,131.77
6. Step 6: Final answer
   x = 875.31