Question

**Question 1 of 3 Which of the following is true about the
random variables X, Y, and Z?**

X is binomial with n = 20 and p = .22.

Y is binomial with n = 40 and p = .32.

Z is not binomial. All of the above are true.

Only (A) and (B) are true.

**Question 2 of 3 What is the probability that exactly 2
of the 20 older adults prefer organic? (Note: Some answers are
rounded.)**

.105

190

7.12

.22

.05

**Question 3 of 3 What is the mean and standard deviation
of the random variable Y (the number of younger adults out of 40
who prefer organic)? Answers may be rounded.**

Mean: 12.8 Standard Deviation: 2.95

Mean: 40 Standard Deviation: .32

Mean: .32 Standard Deviation: 40

Mean: 12.8 Standard Deviation: 8.704

We cannot find the mean and standard deviation since the probability distribution table is not given.

Answer #1

A restaurant chain wants to create dishes that will attract new
clientele. They are interested in adding some organic options to
their menu. A survey revealed that 22% of people over 50 and 32% of
people under 50 prefer organic foods. The restaurant wants to poll
their clientele.
60 clients were randomly selected: 20 older adults and 40
younger adults.
Let X be the number of older adults (out of 20) who prefer
organic.
Let Y be the number of...

Let X and Y be two normal random variables. Given that the mean
of X is 6 and its standard deviation is equal to 1, and the mean of
Y is 2 with standard deviation 3. What is the probability that Z=
X-3Y is positive?.

True or False?
19. In a binomial distribution the random variable X is
discrete.
20. The standard deviation and mean are the same for the
standard normal distribution.
21. In a statistical study, the random variable X = 1, if the
house is colonial and X = 0 if the house is not colonial, then it
can be stated that the random variable is continuous. 22. For a
continuous distribution, P(X ≤ 10) is the same as P(X<10).
23. For...

Question 1
A binomial
distribution reflects two possible outcomes, which can be denoted
as "success and failure"
True
False
1 points
Question 2
As a binomial
distribution is discrete, we can not ever use the normal
distribution?
True
False
1 points
Question 3
The text mentions that
in order to use the normal distribution for binomial distributions
that EITHER n(p) OR n(q) must be > 5.
True
False
1 points
Question 4
The reason that both
n(p) and n(q) are...

Question 3
The text mentions that
in order to use the normal distribution for binomial distributions
that EITHER n(p) OR n(q) must be > 5.
True
False
Question 4
The reason that both
n(p) and n(q) are > 5 is that otherwise the distribution is
likely skewed
True
False
Question 5
The reason that the
distribution should not be skewed is that the normal distribution
assumes that symmetrical distribtuion
True
False
Question 6
Using ONLY the 68, 95,
and 99.7...

Let X and Y be random variables with the following distributions
X N~ (20,2) and Y N~ (30,1). The covariance of X and Y is σ XY =
0.25 . Let Z= + 0.75X x 0.25Y . Find the mean and the variance of
Z.

Suppose we have the following paired observations of variables
X and Y:
X Y
18 40
14 30
20 20
22 20
19 10
27 0
Calculate the values of the sample
covariance and sample correlation between X and Y. Using this
information, how would you characterize the relationship between X
and Y?
(12 points)
Suppose X follows a normal distribution with mean µ = 50 and
standard deviation σ = 5.
(10 points)
What is the...

1) Generate a data set with three variables (X, Y and Z). X and
Y have 10 observations for each (N=10), and Z has 13 observations
(N=13). Each observation should have two digits (such as “83” or
“8.3”).
2) Draw a stem-and-leaf display for variable Z only and draw a
box plot display for variable Z after specifying the 5 numbers
(UEX, LEX, FU, FL, MD).
3) Calculate the mean and standard deviation for variable X
4) Calculate the mean...

QUESTION 22
Which one of the following is a correct statement about the
probability distribution of a t random variable?
a.
The mean is zero but the standard deviation is greater than
1.
b.
The mean and standard deviation can be any number.
c.
The mean is zero but the standard deviation is less than 1.
d.
The mean is zero and the standard deviation is 1.
QUESTION 23
A professor finds that for 16 randomly selected students the
time...

X and Y ar i.i.d. exponential random variables
with mean = 2. Let Z = X + Y. The
probability that Z is less than or equal to 3 is:

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