Finding the Fourth Proportional to 1,160.74, 1,601.81 and 636.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,160.74 : 1,601.81 = 636.77 : x
2. Step 2: Convert to fraction form
   1,160.74/1,601.81 = 636.77/x
3. Step 3: Cross multiply
   1,160.74x = 1,601.81 × 636.77
4. Step 4: Simplify right side
   1,160.74x = 1,019,984.55
5. Step 5: Solve for x
   x = 1,019,984.55/1,160.74
6. Step 6: Final answer
   x = 878.74