Answer:
x=-5 & y=3
Step-by step explanation:
Answer:
H
Step-by-step explanation:
Answer:
Michelle must get an 80 on her next test to keep her average score.
Step-by-step explanation:
Since Michelle got an average score of 80 on two tests, to determine what score she must get on the third test so that her average score for the three tests is the same as the average score for the first two tests, the following calculation must be performed:
X / 2 = 80
X = 80 x 2
X = 160
X x 3 = 80 x 3
X x 3 = 240
X = 240/3
x = 80
So, Michelle must get an 80 on her next test to keep her average score.
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
Answer:
Sale tax rate = 7.5%
Step-by-step explanation:
The book cost $12.95
If you take 12.95 x 0.075 = 0.97125
Round the answerto the hundredth (0.97)
Add the tax, 12.95 + 0.97 = 13.92
