Finding the Fourth Proportional to 2,147.87, 3,222.51 and 916.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,147.87 : 3,222.51 = 916.31 : x
2. Step 2: Convert to fraction form
   2,147.87/3,222.51 = 916.31/x
3. Step 3: Cross multiply
   2,147.87x = 3,222.51 × 916.31
4. Step 4: Simplify right side
   2,147.87x = 2,952,802.03
5. Step 5: Solve for x
   x = 2,952,802.03/2,147.87
6. Step 6: Final answer
   x = 1,374.76