Finding the Fourth Proportional to 1,322.40, 1,980.72 and 1,066.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,322.40 : 1,980.72 = 1,066.08 : x
2. Step 2: Convert to fraction form
   1,322.40/1,980.72 = 1,066.08/x
3. Step 3: Cross multiply
   1,322.40x = 1,980.72 × 1,066.08
4. Step 4: Simplify right side
   1,322.40x = 2,111,605.98
5. Step 5: Solve for x
   x = 2,111,605.98/1,322.40
6. Step 6: Final answer
   x = 1,596.80