Finding the Fourth Proportional to 1,200.21, 1,656.31 and 669.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.21 : 1,656.31 = 669.08 : x
2. Step 2: Convert to fraction form
   1,200.21/1,656.31 = 669.08/x
3. Step 3: Cross multiply
   1,200.21x = 1,656.31 × 669.08
4. Step 4: Simplify right side
   1,200.21x = 1,108,200.15
5. Step 5: Solve for x
   x = 1,108,200.15/1,200.21
6. Step 6: Final answer
   x = 923.34