Finding the Fourth Proportional to 2,156.50, 3,236.10 and 858.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,156.50 : 3,236.10 = 858.07 : x
2. Step 2: Convert to fraction form
   2,156.50/3,236.10 = 858.07/x
3. Step 3: Cross multiply
   2,156.50x = 3,236.10 × 858.07
4. Step 4: Simplify right side
   2,156.50x = 2,776,800.33
5. Step 5: Solve for x
   x = 2,776,800.33/2,156.50
6. Step 6: Final answer
   x = 1,287.64