Finding the Fourth Proportional to 2,645.10, 3,968.12 and 890.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,645.10 : 3,968.12 = 890.28 : x
2. Step 2: Convert to fraction form
   2,645.10/3,968.12 = 890.28/x
3. Step 3: Cross multiply
   2,645.10x = 3,968.12 × 890.28
4. Step 4: Simplify right side
   2,645.10x = 3,532,740.10
5. Step 5: Solve for x
   x = 3,532,740.10/2,645.10
6. Step 6: Final answer
   x = 1,335.58