Answer:
5.4
Step-by-step explanation:
7.2/4 =1.8
3x1.8 = 5.4
Answer:
(a) σ² = 144
(b) s² = 12
Step-by-step explanation:
(a) Population variance σ² = ∑(X -
)² / N
The arithmetic mean 


σ² = 
= 
= 
= 
σ² = 144
(b) 

= 12
I think it would be the last one. I hope this helped!
Answer:
x is +1
y is-5
Step-by-step explanation: