Finding the Fourth Proportional to 1,091.21, 1,635.51 and 505.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.21 : 1,635.51 = 505.42 : x
2. Step 2: Convert to fraction form
   1,091.21/1,635.51 = 505.42/x
3. Step 3: Cross multiply
   1,091.21x = 1,635.51 × 505.42
4. Step 4: Simplify right side
   1,091.21x = 826,614.43
5. Step 5: Solve for x
   x = 826,614.43/1,091.21
6. Step 6: Final answer
   x = 757.52