Finding the Fourth Proportional to 2,622.84, 3,931.32 and 1,321.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,622.84 : 3,931.32 = 1,321.57 : x
2. Step 2: Convert to fraction form
   2,622.84/3,931.32 = 1,321.57/x
3. Step 3: Cross multiply
   2,622.84x = 3,931.32 × 1,321.57
4. Step 4: Simplify right side
   2,622.84x = 5,195,514.57
5. Step 5: Solve for x
   x = 5,195,514.57/2,622.84
6. Step 6: Final answer
   x = 1,980.87