Finding the Fourth Proportional to 2,117.02, 2,921.37 and 1,172.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,117.02 : 2,921.37 = 1,172.78 : x
2. Step 2: Convert to fraction form
   2,117.02/2,921.37 = 1,172.78/x
3. Step 3: Cross multiply
   2,117.02x = 2,921.37 × 1,172.78
4. Step 4: Simplify right side
   2,117.02x = 3,426,124.31
5. Step 5: Solve for x
   x = 3,426,124.31/2,117.02
6. Step 6: Final answer
   x = 1,618.38