Finding the Fourth Proportional to 1,189.31, 1,642.01 and 816.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.31 : 1,642.01 = 816.17 : x
2. Step 2: Convert to fraction form
   1,189.31/1,642.01 = 816.17/x
3. Step 3: Cross multiply
   1,189.31x = 1,642.01 × 816.17
4. Step 4: Simplify right side
   1,189.31x = 1,340,147.01
5. Step 5: Solve for x
   x = 1,340,147.01/1,189.31
6. Step 6: Final answer
   x = 1,126.83