Finding the Fourth Proportional to 1,172.21, 1,617.85 and 674.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.21 : 1,617.85 = 674.76 : x
2. Step 2: Convert to fraction form
   1,172.21/1,617.85 = 674.76/x
3. Step 3: Cross multiply
   1,172.21x = 1,617.85 × 674.76
4. Step 4: Simplify right side
   1,172.21x = 1,091,665.61
5. Step 5: Solve for x
   x = 1,091,665.61/1,172.21
6. Step 6: Final answer
   x = 931.28