Finding the Fourth Proportional to 1,014.21, 1,399.59 and 664.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,014.21 : 1,399.59 = 664.88 : x
2. Step 2: Convert to fraction form
   1,014.21/1,399.59 = 664.88/x
3. Step 3: Cross multiply
   1,014.21x = 1,399.59 × 664.88
4. Step 4: Simplify right side
   1,014.21x = 930,552.40
5. Step 5: Solve for x
   x = 930,552.40/1,014.21
6. Step 6: Final answer
   x = 917.51