Finding the Fourth Proportional to 1,620.24, 2,427.57 and 1,275.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,620.24 : 2,427.57 = 1,275.78 : x
2. Step 2: Convert to fraction form
   1,620.24/2,427.57 = 1,275.78/x
3. Step 3: Cross multiply
   1,620.24x = 2,427.57 × 1,275.78
4. Step 4: Simplify right side
   1,620.24x = 3,097,045.25
5. Step 5: Solve for x
   x = 3,097,045.25/1,620.24
6. Step 6: Final answer
   x = 1,911.47