Finding the Fourth Proportional to 2,142.20, 3,210.60 and 1,167.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.20 : 3,210.60 = 1,167.50 : x
2. Step 2: Convert to fraction form
   2,142.20/3,210.60 = 1,167.50/x
3. Step 3: Cross multiply
   2,142.20x = 3,210.60 × 1,167.50
4. Step 4: Simplify right side
   2,142.20x = 3,748,375.50
5. Step 5: Solve for x
   x = 3,748,375.50/2,142.20
6. Step 6: Final answer
   x = 1,749.78