Answer:
134.5 degree
Step-by-step explanation:
first find the remaining side of a triangle
BY using cosine rule
C^2=A^2+B^2-2ABcosx
apply square root both sides
√c^2 =√[4^2+10^2-2(4)(10)cos29]
C=√(116-69.96958)
C=√46.03
C=6.8
Now find angle using cosine rule
C^2=A^2+B^2-2ABcosx
10^2=4^2+6.78^2-2(4)(6.78)cosx
100=16+45.9684-54.24cosx
100=61.9684-54.24cosx
100-61.9684=-54.24cosx
(38.0316)/-54.24=(-54.4cosx)/-54.24
-0.70117=cosx
X= cos inverse of -0.70117
x=134.5 degree
Using the binomial distribution, it is found that there is a 0.0328 = 3.28% probability that at least 2 of them choose the same quote.
<h3>What is the binomial distribution formula?</h3>
The formula is:
![P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20C_%7Bn%2Cx%7D.p%5E%7Bx%7D.%281-p%29%5E%7Bn-x%7D)
![C_{n,x} = \frac{n!}{x!(n-x)!}](https://tex.z-dn.net/?f=C_%7Bn%2Cx%7D%20%3D%20%5Cfrac%7Bn%21%7D%7Bx%21%28n-x%29%21%7D)
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem, we have that:
- There are 6 students, hence n = 6.
- There are 20 quotes, hence the probability of each being chosen is p = 1/20 = 0.05.
The probability of one quote being chosen at least two times is given by:
![P(X \geq 2) = 1 - P(X < 2)](https://tex.z-dn.net/?f=P%28X%20%5Cgeq%202%29%20%3D%201%20-%20P%28X%20%3C%202%29)
In which:
P(X < 2) = P(X = 0) + P(X = 1).
Then:
![P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20C_%7Bn%2Cx%7D.p%5E%7Bx%7D.%281-p%29%5E%7Bn-x%7D)
![P(X = 0) = C_{6,0}.(0.05)^{0}.(0.95)^{6} = 0.7351](https://tex.z-dn.net/?f=P%28X%20%3D%200%29%20%3D%20C_%7B6%2C0%7D.%280.05%29%5E%7B0%7D.%280.95%29%5E%7B6%7D%20%3D%200.7351)
![P(X = 1) = C_{6,1}.(0.05)^{1}.(0.95)^{5} = 0.2321](https://tex.z-dn.net/?f=P%28X%20%3D%201%29%20%3D%20C_%7B6%2C1%7D.%280.05%29%5E%7B1%7D.%280.95%29%5E%7B5%7D%20%3D%200.2321)
Then:
P(X < 2) = P(X = 0) + P(X = 1) = 0.7351 + 0.2321 = 0.9672.
![P(X \geq 2) = 1 - P(X < 2) = 1 - 0.9672 = 0.0328](https://tex.z-dn.net/?f=P%28X%20%5Cgeq%202%29%20%3D%201%20-%20P%28X%20%3C%202%29%20%3D%201%20-%200.9672%20%3D%200.0328)
0.0328 = 3.28% probability that at least 2 of them choose the same quote.
More can be learned about the binomial distribution at brainly.com/question/24863377
15 is A, 22+X=8
I don't have time to solve the rest RN but will come back later