Finding the Fourth Proportional to 2,156.12, 2,974.62 and 1,316.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,156.12 : 2,974.62 = 1,316.15 : x
2. Step 2: Convert to fraction form
   2,156.12/2,974.62 = 1,316.15/x
3. Step 3: Cross multiply
   2,156.12x = 2,974.62 × 1,316.15
4. Step 4: Simplify right side
   2,156.12x = 3,915,047.33
5. Step 5: Solve for x
   x = 3,915,047.33/2,156.12
6. Step 6: Final answer
   x = 1,815.78