Finding the Fourth Proportional to 1,688.01, 2,532.72 and 810.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,688.01 : 2,532.72 = 810.98 : x
2. Step 2: Convert to fraction form
   1,688.01/2,532.72 = 810.98/x
3. Step 3: Cross multiply
   1,688.01x = 2,532.72 × 810.98
4. Step 4: Simplify right side
   1,688.01x = 2,053,972.60
5. Step 5: Solve for x
   x = 2,053,972.60/1,688.01
6. Step 6: Final answer
   x = 1,216.80