Finding the Fourth Proportional to 754.21, 1,128.89 and 406.72

Step by Step Solution

1. Step 1: Write the proportion equation
   754.21 : 1,128.89 = 406.72 : x
2. Step 2: Convert to fraction form
   754.21/1,128.89 = 406.72/x
3. Step 3: Cross multiply
   754.21x = 1,128.89 × 406.72
4. Step 4: Simplify right side
   754.21x = 459,142.28
5. Step 5: Solve for x
   x = 459,142.28/754.21
6. Step 6: Final answer
   x = 608.77