Finding the Fourth Proportional to 2,213.28, 3,056.40 and 1,386.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,213.28 : 3,056.40 = 1,386.72 : x
2. Step 2: Convert to fraction form
   2,213.28/3,056.40 = 1,386.72/x
3. Step 3: Cross multiply
   2,213.28x = 3,056.40 × 1,386.72
4. Step 4: Simplify right side
   2,213.28x = 4,238,371.01
5. Step 5: Solve for x
   x = 4,238,371.01/2,213.28
6. Step 6: Final answer
   x = 1,914.97