Finding the Fourth Proportional to 2,152.50, 2,970.45 and 1,221.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,152.50 : 2,970.45 = 1,221.06 : x
2. Step 2: Convert to fraction form
   2,152.50/2,970.45 = 1,221.06/x
3. Step 3: Cross multiply
   2,152.50x = 2,970.45 × 1,221.06
4. Step 4: Simplify right side
   2,152.50x = 3,627,097.68
5. Step 5: Solve for x
   x = 3,627,097.68/2,152.50
6. Step 6: Final answer
   x = 1,685.06