Finding the Fourth Proportional to 2,071.35, 2,858.57 and 1,187.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.35 : 2,858.57 = 1,187.30 : x
2. Step 2: Convert to fraction form
   2,071.35/2,858.57 = 1,187.30/x
3. Step 3: Cross multiply
   2,071.35x = 2,858.57 × 1,187.30
4. Step 4: Simplify right side
   2,071.35x = 3,393,980.16
5. Step 5: Solve for x
   x = 3,393,980.16/2,071.35
6. Step 6: Final answer
   x = 1,638.54