Finding the Fourth Proportional to 2,145.78, 3,219.72 and 976.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.78 : 3,219.72 = 976.56 : x
2. Step 2: Convert to fraction form
   2,145.78/3,219.72 = 976.56/x
3. Step 3: Cross multiply
   2,145.78x = 3,219.72 × 976.56
4. Step 4: Simplify right side
   2,145.78x = 3,144,249.76
5. Step 5: Solve for x
   x = 3,144,249.76/2,145.78
6. Step 6: Final answer
   x = 1,465.32