Finding the Fourth Proportional to 1,131.61, 1,561.59 and 634.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.61 : 1,561.59 = 634.28 : x
2. Step 2: Convert to fraction form
   1,131.61/1,561.59 = 634.28/x
3. Step 3: Cross multiply
   1,131.61x = 1,561.59 × 634.28
4. Step 4: Simplify right side
   1,131.61x = 990,477.50
5. Step 5: Solve for x
   x = 990,477.50/1,131.61
6. Step 6: Final answer
   x = 875.28