Answer:
a) The correct option is C: 4x
b) The correct option is B: 2x
Step-by-step explanation:
a) Usually when we have a real number multiplying a variable, we do not need to write the multiplication symbol.
So instead of writing:
4×x
We can write:
4x
And this will be equivalent.
Then in this case the correct option is C.
b) We know that if we have the multiplication of A by n, this will be equivalent to add A n times.
Then if we have the sum of A, for example, 4 times, we have:
A + A + A + A
And this can be written as 4*A
In this case, we have the expression x + x.
So we are adding x two times, then this can be written as: 2*x, or, as we said earlier, this also can be written as 2x.
Then the correct option is option B.
Answer:
a) p=0.2
b) probability of passing is 0.01696
.
c) The expected value of correct questions is 1.2
Step-by-step explanation:
a) Since each question has 5 options, all of them equally likely, and only one correct answer, then the probability of having a correct answer is 1/5 = 0.2.
b) Let X be the number of correct answers. We will model this situation by considering X as a binomial random variable with a success probability of p=0.2 and having n=6 samples. We have the following for k=0,1,2,3,4,5,6
.
Recall that
In this case, the student passes if X is at least four correct questions, then

c)The expected value of a binomial random variable with parameters n and p is
. IN our case, n=6 and p =0.2. Then the expected value of correct answers is 
Answer:
sorry
Step-by-step explanation:
Answer:
6.68% of the female college-bound high school seniors had scores above 575.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 500
Standard Deviation, σ = 50
We are given that the distribution of score is a bell shaped distribution that is a normal distribution.
Formula:
P(scores above 575)
P(x > 575)
Calculation the value from standard normal z table, we have,
6.68% of the female college-bound high school seniors had scores above 575.