Finding the Fourth Proportional to 1,440.22, 1,987.48 and 810.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,440.22 : 1,987.48 = 810.75 : x
2. Step 2: Convert to fraction form
   1,440.22/1,987.48 = 810.75/x
3. Step 3: Cross multiply
   1,440.22x = 1,987.48 × 810.75
4. Step 4: Simplify right side
   1,440.22x = 1,611,345.04
5. Step 5: Solve for x
   x = 1,611,345.04/1,440.22
6. Step 6: Final answer
   x = 1,118.82