Finding the Fourth Proportional to 1,321.83, 1,985.22 and 1,213.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.83 : 1,985.22 = 1,213.47 : x
2. Step 2: Convert to fraction form
   1,321.83/1,985.22 = 1,213.47/x
3. Step 3: Cross multiply
   1,321.83x = 1,985.22 × 1,213.47
4. Step 4: Simplify right side
   1,321.83x = 2,409,004.91
5. Step 5: Solve for x
   x = 2,409,004.91/1,321.83
6. Step 6: Final answer
   x = 1,822.48