Finding the Fourth Proportional to 1,406.44, 1,938.18 and 991.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,406.44 : 1,938.18 = 991.72 : x
2. Step 2: Convert to fraction form
   1,406.44/1,938.18 = 991.72/x
3. Step 3: Cross multiply
   1,406.44x = 1,938.18 × 991.72
4. Step 4: Simplify right side
   1,406.44x = 1,922,131.87
5. Step 5: Solve for x
   x = 1,922,131.87/1,406.44
6. Step 6: Final answer
   x = 1,366.66