Finding the Fourth Proportional to 1,421.28, 1,961.24 and 791.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.28 : 1,961.24 = 791.69 : x
2. Step 2: Convert to fraction form
   1,421.28/1,961.24 = 791.69/x
3. Step 3: Cross multiply
   1,421.28x = 1,961.24 × 791.69
4. Step 4: Simplify right side
   1,421.28x = 1,552,680.33
5. Step 5: Solve for x
   x = 1,552,680.33/1,421.28
6. Step 6: Final answer
   x = 1,092.45