Finding the Fourth Proportional to 1,388.07, 2,083.12 and 772.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.07 : 2,083.12 = 772.29 : x
2. Step 2: Convert to fraction form
   1,388.07/2,083.12 = 772.29/x
3. Step 3: Cross multiply
   1,388.07x = 2,083.12 × 772.29
4. Step 4: Simplify right side
   1,388.07x = 1,608,770.81
5. Step 5: Solve for x
   x = 1,608,770.81/1,388.07
6. Step 6: Final answer
   x = 1,159.00