Finding the Fourth Proportional to 2,152.52, 2,970.42 and 1,221

Step by Step Solution

1. Step 1: Write the proportion equation
   2,152.52 : 2,970.42 = 1,221 : x
2. Step 2: Convert to fraction form
   2,152.52/2,970.42 = 1,221/x
3. Step 3: Cross multiply
   2,152.52x = 2,970.42 × 1,221
4. Step 4: Simplify right side
   2,152.52x = 3,626,882.82
5. Step 5: Solve for x
   x = 3,626,882.82/2,152.52
6. Step 6: Final answer
   x = 1,684.95