Finding the Fourth Proportional to 1,570.89, 2,167.86 and 872.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.89 : 2,167.86 = 872.31 : x
2. Step 2: Convert to fraction form
   1,570.89/2,167.86 = 872.31/x
3. Step 3: Cross multiply
   1,570.89x = 2,167.86 × 872.31
4. Step 4: Simplify right side
   1,570.89x = 1,891,045.96
5. Step 5: Solve for x
   x = 1,891,045.96/1,570.89
6. Step 6: Final answer
   x = 1,203.81