Finding the Fourth Proportional to 2,661.18, 3,971.00 and 2,645.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.18 : 3,971.00 = 2,645.88 : x
2. Step 2: Convert to fraction form
   2,661.18/3,971.00 = 2,645.88/x
3. Step 3: Cross multiply
   2,661.18x = 3,971.00 × 2,645.88
4. Step 4: Simplify right side
   2,661.18x = 10,506,776.25
5. Step 5: Solve for x
   x = 10,506,776.25/2,661.18
6. Step 6: Final answer
   x = 3,948.16