Finding the Fourth Proportional to 1,004.21, 1,386.02 and 584.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,004.21 : 1,386.02 = 584.50 : x
2. Step 2: Convert to fraction form
   1,004.21/1,386.02 = 584.50/x
3. Step 3: Cross multiply
   1,004.21x = 1,386.02 × 584.50
4. Step 4: Simplify right side
   1,004.21x = 810,128.69
5. Step 5: Solve for x
   x = 810,128.69/1,004.21
6. Step 6: Final answer
   x = 806.73