Answer:
Pythagoras Theorem
Step-by-step explanation:
For any triangle ABC, the law of cosine is given by
Now, let us suppose the triangle ABC is a right triangle having right angle at C.
Thus, C = 90°
Substituting this value in above formula
We know that cos 90°= 0
Thus, the equation becomes
We can see that it reduces to Pythagoras Theorem.
Hence, we can conclude that law of cosines reduce to Pythagoras Theorem when dealing with a right triangle
(a) 1
(b) 0.3
(c) 0.15
(d) 0.27
(a) The cumulative probability distribution of the random variable X for the year 2020 is:
X = 0, P(X<=0) = 0.2
X = 1, P(X<=1) = 0.6
X = 2, P(X<=2) = 0.9
X = 3, P(X<=3) = 1
Graph:
(b) P(1 ≤ X < 3) = P(X<=2) - P(X<=1) = 0.9 - 0.6 = 0.3
(c) The joint probability distribution of the variables X and Y for the year 2020 is:
X = 0, Y = 0, P(X=0, Y=0) = 0.15
X = 0, Y = 1, P(X=0, Y=1) = 0.25
X = 0, Y = 2, P(X=0, Y=2) = 0.05
X = 1, Y = 0, P(X=1, Y=0) = 0.2
X = 1, Y = 1, P(X=1, Y=1) = 0.4
X = 1, Y = 2, P(X=1, Y=2) = 0.2
X = 2, Y = 0, P(X=2, Y=0) = 0.3
X = 2, Y = 1, P(X=2, Y=1) = 0.3
X = 2, Y = 2, P(X=2, Y=2) = 0.2
X = 3, Y = 0, P(X=3, Y=0) = 0.15
X = 3, Y = 1, P(X=3, Y=1) = 0.15
X = 3, Y = 2, P(X=3, Y=2) = 0.15
(d) Treating the answer from question 3(c) as the joint probability distribution in the population, the correlation between X and Y is 0.27.
Learn more about probability
#SPJ4