Finding the Fourth Proportional to 1,433.16, 1,978.02 and 991.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,433.16 : 1,978.02 = 991.62 : x
2. Step 2: Convert to fraction form
   1,433.16/1,978.02 = 991.62/x
3. Step 3: Cross multiply
   1,433.16x = 1,978.02 × 991.62
4. Step 4: Simplify right side
   1,433.16x = 1,961,444.19
5. Step 5: Solve for x
   x = 1,961,444.19/1,433.16
6. Step 6: Final answer
   x = 1,368.61