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 = 
Answer:
hey:)
12:15-8:15=4hr
17:30-13:00=4:30hr
4+4:30=8:30hr
$11/hr therefore:
8:30×11= 8.5×11=93.5
and now round it to the nearest hundredth:) I hope this was helpful
Answer with explanation:
It is given that for three integers , a, b and c, if

Since , a b is divisible by c , following are the possibilities
1.→ a and b are prime integers .Then , c will be prime number either equal to a or b.
2.→a and b are not prime integers ,then any of the factors of a or b will be equal to c.For example:
⇒a=m × n
b=p × q× c
or,
⇒a=u×v×c
b=s×t
So, whatever the integral values taken by a, and b, if
then either of
is true.
Answer:
19
Step-by-step explanation:
The triangle is an isosceles and so angle SRT and angle STR are equal
also:
Angle SRT and angle STU are supplementary so their sum is equal to 180
7x + 2x + 9 = 180 add like terms
9x + 9 = 180 subtract 9 from both sides
9x = 171 divide both sides by 9
x = 19
Answer:
4
Step-by-step explanation:
It's AoPS question