Finding the Fourth Proportional to 2,187.68, 3,019.63 and 1,431.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,187.68 : 3,019.63 = 1,431.57 : x
2. Step 2: Convert to fraction form
   2,187.68/3,019.63 = 1,431.57/x
3. Step 3: Cross multiply
   2,187.68x = 3,019.63 × 1,431.57
4. Step 4: Simplify right side
   2,187.68x = 4,322,811.72
5. Step 5: Solve for x
   x = 4,322,811.72/2,187.68
6. Step 6: Final answer
   x = 1,975.98