Finding the Fourth Proportional to 2,091.60, 3,136.68 and 936.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,091.60 : 3,136.68 = 936.72 : x
2. Step 2: Convert to fraction form
   2,091.60/3,136.68 = 936.72/x
3. Step 3: Cross multiply
   2,091.60x = 3,136.68 × 936.72
4. Step 4: Simplify right side
   2,091.60x = 2,938,190.89
5. Step 5: Solve for x
   x = 2,938,190.89/2,091.60
6. Step 6: Final answer
   x = 1,404.76