Finding the Fourth Proportional to 1,985.15, 2,740.50 and 1,388.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.15 : 2,740.50 = 1,388.18 : x
2. Step 2: Convert to fraction form
   1,985.15/2,740.50 = 1,388.18/x
3. Step 3: Cross multiply
   1,985.15x = 2,740.50 × 1,388.18
4. Step 4: Simplify right side
   1,985.15x = 3,804,293.59
5. Step 5: Solve for x
   x = 3,804,293.59/1,985.15
6. Step 6: Final answer
   x = 1,916.38