Answer:
45% probability that a randomly selected customer saw the advertisement on the internet or on television
Step-by-step explanation:
We solve this problem building the Venn's diagram of these probabilities.
I am going to say that:
A is the probability that a customer saw the advertisement on the internet.
B is the probability that a customer saw the advertisement on television.
We have that:

In which a is the probability that a customer saw the advertisement on the internet but not on television and
is the probability that the customers saw the advertisement in both the internet and on television.
By the same logic, we have that:

12% saw it on both the internet and on television.
This means that 
20% saw it on television
This means that 
37% of customers saw the advertisement on the internet
This means that 
What is the probability that a randomly selected customer saw the advertisement on the internet or on television

45% probability that a randomly selected customer saw the advertisement on the internet or on television
If triangle RST and triangle XYZ are similar, the statement that must be true is :
Angle R equals angle X
Triangle R S T
Triangle X Y Z
those three angles will be similar in this case
hope this helps
Answer:


Step-by-step explanation:
To solve this question we're going to use trigonometric identities and good ol' Pythagoras theorem.
a) Firstly, sec(θ)=52. we're gonna convert this to cos(θ) using:

we can substitute the value of sec(θ) in this equation:

and solve for for cos(θ)

side note: just to confirm we can find the value of θ and verify that is indeed an acute angle by
b) since right triangle is mentioned in the question. We can use:

we know the value of cos(θ)=1\52. and by comparing the two. we can say that:
- length of the adjacent side = 1
- length of the hypotenuse = 52
we can find the third side using the Pythagoras theorem.




- length of the opposite side = √(2703) ≈ 51.9904
we can find the sin(θ) using this side:


and since 

Answer: 11. Is A
Step-by-step explanation:
Answer:C. (77.29, 85.71)
Step-by-step explanation:
We want to determine a 95% confidence interval for the mean test score of randomly selected students.
Number of sample, n = 25
Mean, u = 81.5
Standard deviation, s = 10.2
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
81.5 +/- 1.96 × 10.2/√25
= 81.5 +/- 1.96 × 2.04
= 81.5 +/- 3.9984
The lower end of the confidence interval is 81.5 - 3.9984 =77.5016
The upper end of the confidence interval is 81.5 + 3.9984 =85.4984
Therefore, the correct option is
C. (77.29, 85.71)