Finding the Fourth Proportional to 2,071.39, 2,857.59 and 1,398.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,071.39 : 2,857.59 = 1,398.98 : x
2. Step 2: Convert to fraction form
   2,071.39/2,857.59 = 1,398.98/x
3. Step 3: Cross multiply
   2,071.39x = 2,857.59 × 1,398.98
4. Step 4: Simplify right side
   2,071.39x = 3,997,707.69
5. Step 5: Solve for x
   x = 3,997,707.69/2,071.39
6. Step 6: Final answer
   x = 1,929.96