Finding the Fourth Proportional to 1,912.96, 2,870.15 and 987.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,912.96 : 2,870.15 = 987.92 : x
2. Step 2: Convert to fraction form
   1,912.96/2,870.15 = 987.92/x
3. Step 3: Cross multiply
   1,912.96x = 2,870.15 × 987.92
4. Step 4: Simplify right side
   1,912.96x = 2,835,480.82
5. Step 5: Solve for x
   x = 2,835,480.82/1,912.96
6. Step 6: Final answer
   x = 1,482.25