Finding the Fourth Proportional to 1,356.67, 1,872.21 and 858.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.67 : 1,872.21 = 858.79 : x
2. Step 2: Convert to fraction form
   1,356.67/1,872.21 = 858.79/x
3. Step 3: Cross multiply
   1,356.67x = 1,872.21 × 858.79
4. Step 4: Simplify right side
   1,356.67x = 1,607,835.23
5. Step 5: Solve for x
   x = 1,607,835.23/1,356.67
6. Step 6: Final answer
   x = 1,185.13