Finding the Fourth Proportional to 1,393.08, 1,926.63 and 1,218.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.08 : 1,926.63 = 1,218.12 : x
2. Step 2: Convert to fraction form
   1,393.08/1,926.63 = 1,218.12/x
3. Step 3: Cross multiply
   1,393.08x = 1,926.63 × 1,218.12
4. Step 4: Simplify right side
   1,393.08x = 2,346,866.54
5. Step 5: Solve for x
   x = 2,346,866.54/1,393.08
6. Step 6: Final answer
   x = 1,684.66