Finding the Fourth Proportional to 1,570.92, 2,167.88 and 862.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.92 : 2,167.88 = 862.78 : x
2. Step 2: Convert to fraction form
   1,570.92/2,167.88 = 862.78/x
3. Step 3: Cross multiply
   1,570.92x = 2,167.88 × 862.78
4. Step 4: Simplify right side
   1,570.92x = 1,870,403.51
5. Step 5: Solve for x
   x = 1,870,403.51/1,570.92
6. Step 6: Final answer
   x = 1,190.64