Finding the Fourth Proportional to 2,111.60, 2,907.96 and 1,521.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.60 : 2,907.96 = 1,521.20 : x
2. Step 2: Convert to fraction form
   2,111.60/2,907.96 = 1,521.20/x
3. Step 3: Cross multiply
   2,111.60x = 2,907.96 × 1,521.20
4. Step 4: Simplify right side
   2,111.60x = 4,423,588.75
5. Step 5: Solve for x
   x = 4,423,588.75/2,111.60
6. Step 6: Final answer
   x = 2,094.90