Finding the Fourth Proportional to 2,086.21, 2,879.28 and 1,189.94

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.21 : 2,879.28 = 1,189.94 : x
2. Step 2: Convert to fraction form
   2,086.21/2,879.28 = 1,189.94/x
3. Step 3: Cross multiply
   2,086.21x = 2,879.28 × 1,189.94
4. Step 4: Simplify right side
   2,086.21x = 3,426,172.24
5. Step 5: Solve for x
   x = 3,426,172.24/2,086.21
6. Step 6: Final answer
   x = 1,642.30