Finding the Fourth Proportional to 2,155.81, 2,974.20 and 1,315.93

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.81 : 2,974.20 = 1,315.93 : x
2. Step 2: Convert to fraction form
   2,155.81/2,974.20 = 1,315.93/x
3. Step 3: Cross multiply
   2,155.81x = 2,974.20 × 1,315.93
4. Step 4: Simplify right side
   2,155.81x = 3,913,839.01
5. Step 5: Solve for x
   x = 3,913,839.01/2,155.81
6. Step 6: Final answer
   x = 1,815.48