Finding the Fourth Proportional to 2,071.38, 2,858.91 and 1,187.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.38 : 2,858.91 = 1,187.78 : x
2. Step 2: Convert to fraction form
   2,071.38/2,858.91 = 1,187.78/x
3. Step 3: Cross multiply
   2,071.38x = 2,858.91 × 1,187.78
4. Step 4: Simplify right side
   2,071.38x = 3,395,741.83
5. Step 5: Solve for x
   x = 3,395,741.83/2,071.38
6. Step 6: Final answer
   x = 1,639.36