Answer: (13.4996, 32.5004)
Step-by-step explanation:
The confidence interval for mean difference is given by :-
,
where = sample mean difference .
= critical t value (two-tailed)
SE= Standard error.
Given :
SE= 4.2
Now, the confidence interval for mean difference will be :-
Hence, the required confidence interval : (13.4996, 32.5004)
Answer:
(3,-1)
Step-by-step explanation:
So we have the system of equations:
As directed, add straight down. The y-variable will cancel:
Now, divide both sides by 5. The left cancels:
So x is 3.
Now, substitute 3 for x in either of the equations:
Substitute 3 for x:
Multiply:
Subtract 9 from both sides:
So, our answer is: x=3, y=-1 or (3,-1).
And we are done :)