Finding the Fourth Proportional to 1,131.58, 1,561.61 and 634.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.58 : 1,561.61 = 634.20 : x
2. Step 2: Convert to fraction form
   1,131.58/1,561.61 = 634.20/x
3. Step 3: Cross multiply
   1,131.58x = 1,561.61 × 634.20
4. Step 4: Simplify right side
   1,131.58x = 990,368.79
5. Step 5: Solve for x
   x = 990,368.79/1,131.58
6. Step 6: Final answer
   x = 875.21