Finding the Fourth Proportional to 1,388.58, 2,085.51 and 804.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.58 : 2,085.51 = 804.75 : x
2. Step 2: Convert to fraction form
   1,388.58/2,085.51 = 804.75/x
3. Step 3: Cross multiply
   1,388.58x = 2,085.51 × 804.75
4. Step 4: Simplify right side
   1,388.58x = 1,678,314.17
5. Step 5: Solve for x
   x = 1,678,314.17/1,388.58
6. Step 6: Final answer
   x = 1,208.66