Finding the Fourth Proportional to 2,103.55, 2,902.90 and 1,172.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.55 : 2,902.90 = 1,172.05 : x
2. Step 2: Convert to fraction form
   2,103.55/2,902.90 = 1,172.05/x
3. Step 3: Cross multiply
   2,103.55x = 2,902.90 × 1,172.05
4. Step 4: Simplify right side
   2,103.55x = 3,402,343.95
5. Step 5: Solve for x
   x = 3,402,343.95/2,103.55
6. Step 6: Final answer
   x = 1,617.43