Homework Help for Statistics

1.The Ice Chalet offers dozens of different beginning ice-skating classes. All of the class names are put into a bucket. The Monday night (ages 8 to 12) beginning ice-skating class was picked. In that class, there were 64 girls and 16 boys. Suppose that we are interested in the true proportion of girls (ages 8 to 12) in all beginning ice-skating classes at the Ice Chalet. Assume that the children in the selected class are a random sample of the population.

Define the random variable X.

Are they an extreme value or a res presentation sample mean? And what are the z scores? (Look at photo)

A random sample of n = 36 scores is obtained from a normal population with a mean of = 65. If the sample mean is M = 59 , then compute the z'score for the sample mean and determine whether the sample mean is a typical, representative value or an extreme value for each of the following:

A population standard deviation of = 12:

This is _______ as the z-score is _______ 

A population standard deviation of = 30: 

This is _______, as the z- score is _______ 

What are the z scores and are the sample means unlikely/likely? (Look at photo)

Suppose that a researcher developed a drug that she claims increases extroversion. A sample of n=4 participants has a sample mean of M = 115 on a personality assessment after taking the drug. The personality test has a population mean of = 100 and = 30. 1s the sample mean an especially unlikely result based on the population parameters for the personality test? What if the researcher increased the sample to n m 25 and observes the same sample mean of M=115?

What is the probability of randomly selecting a score less than X = 52?

P(X < 52) =

What is the probability of selecting a random sample of n = 9 scores with a mean less than M = 52?

P(M < 52) =

(Look at photo)

What is the probability of selecting a random sample of n = 16 scores with a mean less than M = 52?

P(M < 52) =

What is the range for 95% and 99%?

For random samples of size n=16 selected from a normal distribution with a mean of   and a standard deviation of  , find each of the following.

The range of sample means that defines the middle  of the distribution of sample means:

The range of sample means that defines the middle   of the distribution of sample means:

Scores on a standardized reading test for fourth-grade students form a normal distribution with μ = 71 and σ = 24. What is the probability of obtaining a sample mean greater than M = 63 for each of the following: a sample of n=64 students?

Scores on a standardized reading test for fourth-grade students form a normal distribution with μ = 71 and σ = 24. What is the probability of obtaining a sample mean greater than M = 63 for each of the following: a sample of n=36?

Is the distribution uniform,skewed, or normal?

Is the expected value 94,86,122, or 90?

Is the standard error 4,8,32, or 64?

What is p for n=4, n=16, and n=25?

Please don't round or give in fractions

1)  In a recent survey of college freshman, 42% of students checked the box next to “exercise regularly”, 45% checked the box next to “eat five or more servings of fruits and vegetables a day”, and 21% checked the box “neither.”  Use the appropriate probability notation in your answers to each question.

First, put student responses in the appropriate boxes of our two-way relative frequency table:

Exercise (E)

Totals

Eats fruit and veggies (Fv)

Totals

100%

Use the appropriate probability notation in your answers to each question.

a) What is the joint probability of randomly selecting a surveyed freshman who exercises and eats 5 servings of fruits and vegetables each day?

b)  What is the probability of selecting a freshman who exercises regularly or eats 5 servings of fruits and vegetables each day?

c)  What is the probability of a student not eating fruits or vegetables?

d)  What is the probability of a freshman not exercising regularly and not eating 5 servings of fruits and vegetables each day?

e)  Complete this conditional relative frequency table rounding to the whole nearest percentage (e.g. 12%).

Exercise (E)

Eats fruit and veggies (Fv)

f)  Is there an association between eating fruits and vegetables and exercise?  Explain fully.

2)  In Canada 85% of households have televisions (T).  61% of households have televisions and internet (I) access.  9% have neither.  

a)  Complete the two- way relative frequency table:

I

Total

T

Total

100%

Use the appropriate probability notation in your answers to each question.

b)  What is the probability of selecting a Canadian house at random that has internet access but no television?

c)  What is the conditional probability of selecting a house that has internet given that it has a television?

d)  Of the house that do not have televisions, what is the conditional probability of selecting one that has internet access?

e)  Complete this conditional relative frequency table rounding to the whole nearest percentage (e.g. 12%).

I

T

f)  Is there an association between television ownership and internet access is Canadian homes?

2) In Canada 85% of households have televisions (T). 61% of households have televisions and internet (I) access. 9% have neither.

a) Complete the two- way relative frequency table:

I 𝐼̅ Total

T

̅ 𝑇

Total

Use the appropriate probability notation in your answers to each question.

100%

b) What is the probability of selecting a Canadian house at random that has internet access but no television?

c) What is the conditional probability of selecting a house that has internet given that it has a television?

d) Of the house that do not have televisions, what is the conditional probability of selecting one that has internet access?

e) Complete this conditional relative frequency table rounding to the whole nearest percentage (e.g. 12%).

I 𝐼̅

T

̅ 𝑇

f) Is there an association between television ownership and internet access is Canadian homes?

1) In a recent survey of college freshman, 42% of students checked the box next to “exercise regularly”, 45% checked the box next to “eat five or more servings of fruits and vegetables a day”, and 21% checked the box “neither.” Use the appropriate probability notation in your answers to each question.

First, put student responses in the appropriate boxes of our two-way relative frequency table:

Exercise (E)

̅

𝐸 Totals

100%

Eats fruit and veggies (Fv)

̅̅̅̅ 𝐹𝑣

Totals

Use the appropriate probability notation in your answers to each question.

a) What is the joint probability of randomly selecting a surveyed freshman who exercises and eats 5 servings of fruits and vegetables each day?

b) What is the probability of selecting a freshman who exercises regularly or eats 5 servings of fruits and vegetables each day?

c) What is the probability of a student not eating fruits or vegetables?

d) What is the probability of a freshman not exercising regularly and not eating 5 servings of fruits and vegetables each day?

e) Complete this conditional relative frequency table rounding to the whole nearest percentage (e.g. 12%).

̅ Exercise (E) 𝐸

̅̅̅̅ 𝐹𝑣

f) Is there an association between eating fruits and vegetables and exercise? Explain fully.

2)  In Canada 92% of households have televisions (T).  72% of households have televisions and internet (I) access.  5% have neither.  

a)  Complete the two- way relative frequency table:

I

Total

T

Total

100%

Use the appropriate probability notation in your answers to each question.

b)  What is the probability of selecting a Canadian house at random that has internet access but no television?

c)  What is the conditional probability of selecting a house that has internet given that it has a television?

d)  Of the house that do not have televisions, what is the conditional probability of selecting one that has internet access?

e)  Complete this conditional relative frequency table rounding to the whole nearest percentage (e.g. 12%).

Checked bag yes

Checked bag no

Business traveler yes

Business traveler no

f)  Is there an association between television ownership and internet access is Canadian homes?