Finding the Fourth Proportional to 2,213.40, 3,054.37 and 1,218.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,213.40 : 3,054.37 = 1,218.72 : x
2. Step 2: Convert to fraction form
   2,213.40/3,054.37 = 1,218.72/x
3. Step 3: Cross multiply
   2,213.40x = 3,054.37 × 1,218.72
4. Step 4: Simplify right side
   2,213.40x = 3,722,421.81
5. Step 5: Solve for x
   x = 3,722,421.81/2,213.40
6. Step 6: Final answer
   x = 1,681.77