Finding the Fourth Proportional to 1,190.59, 1,640.76 and 858.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,190.59 : 1,640.76 = 858.42 : x
2. Step 2: Convert to fraction form
   1,190.59/1,640.76 = 858.42/x
3. Step 3: Cross multiply
   1,190.59x = 1,640.76 × 858.42
4. Step 4: Simplify right side
   1,190.59x = 1,408,457.98
5. Step 5: Solve for x
   x = 1,408,457.98/1,190.59
6. Step 6: Final answer
   x = 1,182.99