Finding the Fourth Proportional to 1,019.98, 1,407.75 and 578.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.98 : 1,407.75 = 578.02 : x
2. Step 2: Convert to fraction form
   1,019.98/1,407.75 = 578.02/x
3. Step 3: Cross multiply
   1,019.98x = 1,407.75 × 578.02
4. Step 4: Simplify right side
   1,019.98x = 813,707.66
5. Step 5: Solve for x
   x = 813,707.66/1,019.98
6. Step 6: Final answer
   x = 797.77