Finding the Fourth Proportional to 1,388.99, 2,081.65 and 772.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.99 : 2,081.65 = 772.37 : x
2. Step 2: Convert to fraction form
   1,388.99/2,081.65 = 772.37/x
3. Step 3: Cross multiply
   1,388.99x = 2,081.65 × 772.37
4. Step 4: Simplify right side
   1,388.99x = 1,607,804.01
5. Step 5: Solve for x
   x = 1,607,804.01/1,388.99
6. Step 6: Final answer
   x = 1,157.53