Answer: (Attached)
Graphic below is the answer to your question.
Answer:
The variance of the data is 15.
σ² = 15
Step-by-step explanation:
The mean is given as
X = 8
х | (x - X) | (x - X)
²
12 | 4 | 16
9 | 1 | 1
11 | 3 | 9
5 | -3 | 9
3 | -5 | 25
The variance is given by


Therefore, the variance of the data is 15.
1/5 discount = 4/5 price of washing machine
4/5 × 1200 = $960