Finding the Fourth Proportional to 3,912.96, 5,870.40 and 1,315.92

Step by Step Solution

1. Step 1: Write the proportion equation
   3,912.96 : 5,870.40 = 1,315.92 : x
2. Step 2: Convert to fraction form
   3,912.96/5,870.40 = 1,315.92/x
3. Step 3: Cross multiply
   3,912.96x = 5,870.40 × 1,315.92
4. Step 4: Simplify right side
   3,912.96x = 7,724,976.77
5. Step 5: Solve for x
   x = 7,724,976.77/3,912.96
6. Step 6: Final answer
   x = 1,974.20