Finding the Fourth Proportional to 1,851.15, 2,551.71 and 1,378.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,851.15 : 2,551.71 = 1,378.30 : x
2. Step 2: Convert to fraction form
   1,851.15/2,551.71 = 1,378.30/x
3. Step 3: Cross multiply
   1,851.15x = 2,551.71 × 1,378.30
4. Step 4: Simplify right side
   1,851.15x = 3,517,021.89
5. Step 5: Solve for x
   x = 3,517,021.89/1,851.15
6. Step 6: Final answer
   x = 1,899.91