Finding the Fourth Proportional to 2,070.78, 2,857.56 and 1,186.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,070.78 : 2,857.56 = 1,186.50 : x
2. Step 2: Convert to fraction form
   2,070.78/2,857.56 = 1,186.50/x
3. Step 3: Cross multiply
   2,070.78x = 2,857.56 × 1,186.50
4. Step 4: Simplify right side
   2,070.78x = 3,390,494.94
5. Step 5: Solve for x
   x = 3,390,494.94/2,070.78
6. Step 6: Final answer
   x = 1,637.30