Finding the Fourth Proportional to 2,071.64, 3,106.62 and 838.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.64 : 3,106.62 = 838.72 : x
2. Step 2: Convert to fraction form
   2,071.64/3,106.62 = 838.72/x
3. Step 3: Cross multiply
   2,071.64x = 3,106.62 × 838.72
4. Step 4: Simplify right side
   2,071.64x = 2,605,588.21
5. Step 5: Solve for x
   x = 2,605,588.21/2,071.64
6. Step 6: Final answer
   x = 1,257.74