Finding the Fourth Proportional to 1,388.51, 2,083.69 and 764.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.51 : 2,083.69 = 764.07 : x
2. Step 2: Convert to fraction form
   1,388.51/2,083.69 = 764.07/x
3. Step 3: Cross multiply
   1,388.51x = 2,083.69 × 764.07
4. Step 4: Simplify right side
   1,388.51x = 1,592,078.16
5. Step 5: Solve for x
   x = 1,592,078.16/1,388.51
6. Step 6: Final answer
   x = 1,146.61