Finding the Fourth Proportional to 1,054.21, 1,580.56 and 757.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,054.21 : 1,580.56 = 757.89 : x
2. Step 2: Convert to fraction form
   1,054.21/1,580.56 = 757.89/x
3. Step 3: Cross multiply
   1,054.21x = 1,580.56 × 757.89
4. Step 4: Simplify right side
   1,054.21x = 1,197,888.72
5. Step 5: Solve for x
   x = 1,197,888.72/1,054.21
6. Step 6: Final answer
   x = 1,136.29