Finding the Fourth Proportional to 1,370.58, 1,891.62 and 811.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.58 : 1,891.62 = 811.23 : x
2. Step 2: Convert to fraction form
   1,370.58/1,891.62 = 811.23/x
3. Step 3: Cross multiply
   1,370.58x = 1,891.62 × 811.23
4. Step 4: Simplify right side
   1,370.58x = 1,534,538.89
5. Step 5: Solve for x
   x = 1,534,538.89/1,370.58
6. Step 6: Final answer
   x = 1,119.63