Finding the Fourth Proportional to 1,369.89, 1,890.53 and 810.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.89 : 1,890.53 = 810.69 : x
2. Step 2: Convert to fraction form
   1,369.89/1,890.53 = 810.69/x
3. Step 3: Cross multiply
   1,369.89x = 1,890.53 × 810.69
4. Step 4: Simplify right side
   1,369.89x = 1,532,633.77
5. Step 5: Solve for x
   x = 1,532,633.77/1,369.89
6. Step 6: Final answer
   x = 1,118.80