Answer: (29.35, 40.95)
Step-by-step explanation:
Formula to find the confidence interval for population mean :-

, where
= sample mean.
z*= critical z-value
n= sample size.
= Population standard deviation.
As per given , we have


n= 37
Using z-table, the critical z-value for 95% confidence = z* = 1.96
Then, the confidence interval for the population mean will be :





Hence, a 95% confidence interval for the population mean = (29.35, 40.95)
72degrees that the agngle its easy
Answer:$373.50
Step-by-step explanation:
$498.00 divided by 40 is 12.45
12.45 times 30 is $373.50
Answer:
0.25
Step-by-step explanation:
We have a total of ten student, and three students are randomly selected (without replacement) to participate in a survey. So, the total number of subsets of size 3 is given by 10C3=120.
On the other hand A=Exactly 1 of the three selected is a freshman. We have that three students are freshman in the classroom, we can form 3C1 different subsets of size 1 with the three freshman; besides B=Exactly 2 of the three selected are juniors, and five are juniors in the classroom. We can form 5C2 different subsets of size 2 with the five juniors. By the multiplication rule the number of different subsets of size 3 with exactly 1 freshman and 2 juniors is given by
(3C1)(5C2)=(3)(10)=30 and
Pr(A∩B)=30/120=0.25