Finding the Fourth Proportional to 1,222.59, 1,688.55 and 828.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.59 : 1,688.55 = 828.93 : x
2. Step 2: Convert to fraction form
   1,222.59/1,688.55 = 828.93/x
3. Step 3: Cross multiply
   1,222.59x = 1,688.55 × 828.93
4. Step 4: Simplify right side
   1,222.59x = 1,399,692.98
5. Step 5: Solve for x
   x = 1,399,692.98/1,222.59
6. Step 6: Final answer
   x = 1,144.86