Finding the Fourth Proportional to 1,918.10, 2,648.23 and 1,387.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,918.10 : 2,648.23 = 1,387.89 : x
2. Step 2: Convert to fraction form
   1,918.10/2,648.23 = 1,387.89/x
3. Step 3: Cross multiply
   1,918.10x = 2,648.23 × 1,387.89
4. Step 4: Simplify right side
   1,918.10x = 3,675,448.46
5. Step 5: Solve for x
   x = 3,675,448.46/1,918.10
6. Step 6: Final answer
   x = 1,916.19