Finding the Fourth Proportional to 1,531.72, 2,113.79 and 868.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,531.72 : 2,113.79 = 868.58 : x
2. Step 2: Convert to fraction form
   1,531.72/2,113.79 = 868.58/x
3. Step 3: Cross multiply
   1,531.72x = 2,113.79 × 868.58
4. Step 4: Simplify right side
   1,531.72x = 1,835,980.81
5. Step 5: Solve for x
   x = 1,835,980.81/1,531.72
6. Step 6: Final answer
   x = 1,198.64