Finding the Fourth Proportional to 2,111.90, 3,166.20 and 1,290.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.90 : 3,166.20 = 1,290.02 : x
2. Step 2: Convert to fraction form
   2,111.90/3,166.20 = 1,290.02/x
3. Step 3: Cross multiply
   2,111.90x = 3,166.20 × 1,290.02
4. Step 4: Simplify right side
   2,111.90x = 4,084,461.32
5. Step 5: Solve for x
   x = 4,084,461.32/2,111.90
6. Step 6: Final answer
   x = 1,934.02