Answer:
we can conclude that there is no significant evidence to conclude that the mean score in 2010 differs from the mean score in 2009.
Step-by-step explanation:
H0 : μ = 582
H1 : μ < 582
Test statistic :
T = (xbar - μ) ÷ σ/√n
Xbar = 515 ; n = 20 ; σ = 120
T = (515 - 582) ÷ 120/√20
T = -67 / 26.832815
T = 2.50
Pvalue at t score = 2.50 ; df = 19 is 0.0187
At α = 0.0187
Pvalue > α ; Hence, we fail to reject the Null
Hence, we can conclude that there is no significant evidence to conclude that the mean score in 2010 differs from the mean score in 2009.
I'm pretty sure the answer is D observational study.
Melanie: 15 years old
Kevin: 5 years old
Assume Kevin's present age is x.
That means that 3 years ago, his age would be x - 3.
Melanie's age would be 6(x - 3).
Same thing for 5 years into the future:
Kevin's age would be x + 5.
Melanie's age would be 2(x + 5).
The two equations we have here are:

By subtracting both equations, we are simplified to:
8 = -4x + 28
By solving the equation, we get x = 5.
That means that Kevin's current age is 5 years old.
Melanie's age could be calculated by substituting Kevins'.
6(x - 3) --> 6(5 - 3) --> 12
Since that was 3 years ago, you need to add 3 to 12 to get her current age.
12 + 3 = 15
Melanie's current age is 15 years old.
The numbers of visits a member could go is 82 visits.
Answer:
There is -1, 0, and 1
Step-by-step explanation:
All whole numbers including zero are integers