Finding the Fourth Proportional to 1,811.81, 2,715.89 and 772.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,811.81 : 2,715.89 = 772.49 : x
2. Step 2: Convert to fraction form
   1,811.81/2,715.89 = 772.49/x
3. Step 3: Cross multiply
   1,811.81x = 2,715.89 × 772.49
4. Step 4: Simplify right side
   1,811.81x = 2,097,980.42
5. Step 5: Solve for x
   x = 2,097,980.42/1,811.81
6. Step 6: Final answer
   x = 1,157.95