Finding the Fourth Proportional to 1,412.57, 1,947.31 and 991.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,412.57 : 1,947.31 = 991.64 : x
2. Step 2: Convert to fraction form
   1,412.57/1,947.31 = 991.64/x
3. Step 3: Cross multiply
   1,412.57x = 1,947.31 × 991.64
4. Step 4: Simplify right side
   1,412.57x = 1,931,032.88
5. Step 5: Solve for x
   x = 1,931,032.88/1,412.57
6. Step 6: Final answer
   x = 1,367.03