Finding the Fourth Proportional to 1,370.32, 1,890.61 and 810.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.32 : 1,890.61 = 810.81 : x
2. Step 2: Convert to fraction form
   1,370.32/1,890.61 = 810.81/x
3. Step 3: Cross multiply
   1,370.32x = 1,890.61 × 810.81
4. Step 4: Simplify right side
   1,370.32x = 1,532,923.47
5. Step 5: Solve for x
   x = 1,532,923.47/1,370.32
6. Step 6: Final answer
   x = 1,118.66