Finding the Fourth Proportional to 1,131.90, 1,561.86 and 634.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.90 : 1,561.86 = 634.56 : x
2. Step 2: Convert to fraction form
   1,131.90/1,561.86 = 634.56/x
3. Step 3: Cross multiply
   1,131.90x = 1,561.86 × 634.56
4. Step 4: Simplify right side
   1,131.90x = 991,093.88
5. Step 5: Solve for x
   x = 991,093.88/1,131.90
6. Step 6: Final answer
   x = 875.60