Answer: 
Step-by-step explanation:
The confidence interval for population mean is given by :-
Given : Sample size : n= 35 , large sample (n>30)
Mean difference : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students will be :-
Hence, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students =
where is the question I dont see it
420 would be the middle number.
Hoped I Could Help:)
Answer:
The other end point is: s+ti = 3+9i
Step-by-step explanation:
Mid-Point(M) in the complex plane states that the midpoint of the line segment joining two complex numbers a+bi and s+ti is the average of the numbers at the endpoints.
It is given by: 
Given: The midpoint = -1 + i and the segment has an endpoint at -5 - 7i
Find the other endpoints.
Let a + bi = -5 -7i and let other endpoint s + ti (i represents imaginary )
Here, a = -5 and b = -7 to find s and t.
then;
[Apply Mid-point formula]
On comparing both sides
we get;
and 
To solve for s:
or
-2 = -5+s
Add 5 to both side we have;
-2+5 = -5+s+5
Simplify:
3 = s or
s =3
Now, to solve for t;
2 =-7+t
Add 7 to both sides we get;
2+7 = -7+t+7
Simplify:
9 = t
or
t =9
Therefore, the other end point (s+ti) is, 3+9i
Answer:
10. put a dot on the number 10
Step-by-step explanation:
3-(-5)-(-2)
when subtracting negatives, you actually end up adding
so
3+5+2=10
