Finding the Fourth Proportional to 1,087.82, 1,501.72 and 621.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.82 : 1,501.72 = 621.98 : x
2. Step 2: Convert to fraction form
   1,087.82/1,501.72 = 621.98/x
3. Step 3: Cross multiply
   1,087.82x = 1,501.72 × 621.98
4. Step 4: Simplify right side
   1,087.82x = 934,039.81
5. Step 5: Solve for x
   x = 934,039.81/1,087.82
6. Step 6: Final answer
   x = 858.63