Finding the Fourth Proportional to 2,091.86, 3,136.59 and 860.13

Step by Step Solution

1. Step 1: Write the proportion equation
   2,091.86 : 3,136.59 = 860.13 : x
2. Step 2: Convert to fraction form
   2,091.86/3,136.59 = 860.13/x
3. Step 3: Cross multiply
   2,091.86x = 3,136.59 × 860.13
4. Step 4: Simplify right side
   2,091.86x = 2,697,875.16
5. Step 5: Solve for x
   x = 2,697,875.16/2,091.86
6. Step 6: Final answer
   x = 1,289.70