Finding the Fourth Proportional to 1,935.72, 2,670.40 and 1,138.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,935.72 : 2,670.40 = 1,138.78 : x
2. Step 2: Convert to fraction form
   1,935.72/2,670.40 = 1,138.78/x
3. Step 3: Cross multiply
   1,935.72x = 2,670.40 × 1,138.78
4. Step 4: Simplify right side
   1,935.72x = 3,040,998.11
5. Step 5: Solve for x
   x = 3,040,998.11/1,935.72
6. Step 6: Final answer
   x = 1,570.99