Finding the Fourth Proportional to 1,131.61, 1,561.68 and 634.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.61 : 1,561.68 = 634.36 : x
2. Step 2: Convert to fraction form
   1,131.61/1,561.68 = 634.36/x
3. Step 3: Cross multiply
   1,131.61x = 1,561.68 × 634.36
4. Step 4: Simplify right side
   1,131.61x = 990,667.32
5. Step 5: Solve for x
   x = 990,667.32/1,131.61
6. Step 6: Final answer
   x = 875.45