Finding the Fourth Proportional to 5,131.82, 7,690.70 and 2,788.76

Step by Step Solution

1. Step 1: Write the proportion equation
   5,131.82 : 7,690.70 = 2,788.76 : x
2. Step 2: Convert to fraction form
   5,131.82/7,690.70 = 2,788.76/x
3. Step 3: Cross multiply
   5,131.82x = 7,690.70 × 2,788.76
4. Step 4: Simplify right side
   5,131.82x = 21,447,516.53
5. Step 5: Solve for x
   x = 21,447,516.53/5,131.82
6. Step 6: Final answer
   x = 4,179.32