Finding the Fourth Proportional to 1,131.24, 1,561.06 and 688.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.24 : 1,561.06 = 688.98 : x
2. Step 2: Convert to fraction form
   1,131.24/1,561.06 = 688.98/x
3. Step 3: Cross multiply
   1,131.24x = 1,561.06 × 688.98
4. Step 4: Simplify right side
   1,131.24x = 1,075,539.12
5. Step 5: Solve for x
   x = 1,075,539.12/1,131.24
6. Step 6: Final answer
   x = 950.76