Finding the Fourth Proportional to 1,071.08, 1,604.86 and 810.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.08 : 1,604.86 = 810.72 : x
2. Step 2: Convert to fraction form
   1,071.08/1,604.86 = 810.72/x
3. Step 3: Cross multiply
   1,071.08x = 1,604.86 × 810.72
4. Step 4: Simplify right side
   1,071.08x = 1,301,092.10
5. Step 5: Solve for x
   x = 1,301,092.10/1,071.08
6. Step 6: Final answer
   x = 1,214.75