Finding the Fourth Proportional to 1,019.95, 1,407.55 and 554.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.95 : 1,407.55 = 554.21 : x
2. Step 2: Convert to fraction form
   1,019.95/1,407.55 = 554.21/x
3. Step 3: Cross multiply
   1,019.95x = 1,407.55 × 554.21
4. Step 4: Simplify right side
   1,019.95x = 780,075.51
5. Step 5: Solve for x
   x = 780,075.51/1,019.95
6. Step 6: Final answer
   x = 764.82