Finding the Fourth Proportional to 1,090.58, 1,505.67 and 810.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,090.58 : 1,505.67 = 810.50 : x
2. Step 2: Convert to fraction form
   1,090.58/1,505.67 = 810.50/x
3. Step 3: Cross multiply
   1,090.58x = 1,505.67 × 810.50
4. Step 4: Simplify right side
   1,090.58x = 1,220,338.01
5. Step 5: Solve for x
   x = 1,220,338.01/1,090.58
6. Step 6: Final answer
   x = 1,118.99