Finding the Fourth Proportional to 2,115.95, 2,920.01 and 1,171.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,115.95 : 2,920.01 = 1,171.80 : x
2. Step 2: Convert to fraction form
   2,115.95/2,920.01 = 1,171.80/x
3. Step 3: Cross multiply
   2,115.95x = 2,920.01 × 1,171.80
4. Step 4: Simplify right side
   2,115.95x = 3,421,667.72
5. Step 5: Solve for x
   x = 3,421,667.72/2,115.95
6. Step 6: Final answer
   x = 1,617.08