Finding the Fourth Proportional to 1,312.51, 1,811.28 and 723.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.51 : 1,811.28 = 723.05 : x
2. Step 2: Convert to fraction form
   1,312.51/1,811.28 = 723.05/x
3. Step 3: Cross multiply
   1,312.51x = 1,811.28 × 723.05
4. Step 4: Simplify right side
   1,312.51x = 1,309,633.33
5. Step 5: Solve for x
   x = 1,309,633.33/1,312.51
6. Step 6: Final answer
   x = 997.81