Finding the Fourth Proportional to 1,431.51, 1,975.50 and 810.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.51 : 1,975.50 = 810.51 : x
2. Step 2: Convert to fraction form
   1,431.51/1,975.50 = 810.51/x
3. Step 3: Cross multiply
   1,431.51x = 1,975.50 × 810.51
4. Step 4: Simplify right side
   1,431.51x = 1,601,162.51
5. Step 5: Solve for x
   x = 1,601,162.51/1,431.51
6. Step 6: Final answer
   x = 1,118.51