Questions
A lab tested the ibuprofen content in a drug manufacturer’s headache pills. After testing 500 random...

A lab tested the ibuprofen content in a drug manufacturer’s headache pills. After testing 500 random samples, the mean ibuprofen content was found to be 202 mg with a standard deviation of 10 mg. Construct a 99% confidence interval for the true mean ibuprofen content in all of the manufacturer’s headache pills.

In: Statistics and Probability

You are to test if the average SAT score in the high school students of Ontario...

You are to test if the average SAT score in the high school students of Ontario is greater than 495. You set the hypotheses as below:

H0: µ = 495 vs Ha: µ > 495

If the SRS of 500 students were selected and the standard deviation has been known to 100, with alpha = 0.05, answer the followings.

a.  What is the Type I error?

b. What is the Type II error if the true population mean is 510. Explain it.

c. What is the power if the true population mean is 510? Explain it.

Please show your work and thank you SO much in advance! You are helping a struggling stats student SO much!

In: Statistics and Probability

If the random variable x~N(0,c^2), and g(x)=x^2, find and sketch the distribution and density function of...

If the random variable x~N(0,c^2), and g(x)=x^2, find and sketch the distribution and density function of the random variable y=g(x).

In: Statistics and Probability

Jobs and productivity! How do retail stores rate? One way to answer this question is to...

Jobs and productivity! How do retail stores rate? One way to answer this question is to examine annual profits per employee. The following data give annual profits per employee (in units of 1 thousand dollars per employee) for companies in retail sales. Assume σ ≈ 4.0 thousand dollars.

3.5

6.3

4.1

8.2

8.0

5.4

8.1

5.8

2.6

2.9

8.1

−1.9

11.9

8.2

6.4

4.7

5.5

4.8

3.0

4.3

−6.0

1.5

2.9

4.8

−1.7

9.4

5.5

5.8

4.7

6.2

15.0

4.1

3.7

5.1

4.2

(a) Use a calculator or appropriate computer software to find x for the preceding data. (Round your answer to two decimal places.)
1 thousand dollars per employee

(b) Let us say that the preceding data are representative of the entire sector of retail sales companies. Find an 80% confidence interval for μ, the average annual profit per employee for retail sales. (Round your answers to two decimal places.)

lower limit     2 thousand dollars
upper limit     3 thousand dollars


(c) Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores. No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


(d) Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores. No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


(e) Find an 95% confidence interval for μ, the average annual profit per employee for retail sales. (Round your answers to two decimal places.)

lower limit     6 thousand dollars
upper limit     7 thousand dollars


Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores. No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores. No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    

In: Statistics and Probability

Students enrolled in an introductory statistics course at a university were asked to take a survey...

Students enrolled in an introductory statistics course at a university were asked to take a survey that indicated whether the student’s learning style was more visual or verbal. Each student received a numerical score ranging from -11 to +11. Negative scores indicated a visual learner, and positive scores indicated a verbal learner. The closer the score was to -11 or +11, the stronger the student’s inclination toward that learning style. A score of 0 would indicate neutrality between visual or verbal learning.  For the 39 students who took the survey, the mean score was -2.744, and the standard deviation was 4.988.

A. State the null and alternative hypotheses for testing whether the mean score (among all students at this university) differs from 0.

B. Calculate the value of the t-test statistic for the hypotheses stated in question 1.

C. Determine the p-value of the test as accurately as possible.

D. Summarize the conclusion that you would draw from this test.

E. Comment on whether the technical conditions of this t-test are satisfied.

In: Statistics and Probability

four married couples went to the concert together. They bought tickets for eight adjacent seats in...

four married couples went to the concert together. They bought tickets for eight adjacent seats in a row. They went inside and sat at random at these seats. what is the probability that Mr.and Mrs. Wilson do not sit next to each other

In: Statistics and Probability

1. Please respond to each part of the question with 60-100 words. a)Give an example where...

1. Please respond to each part of the question with 60-100 words.

a)Give an example where confidence interval must be used for statistical inference.

b) Give an example where hypothesis testing must be used for statistical inference.

c) What is P-value?

d) What is the relationship between hypothesis test and confidence interval?

In: Statistics and Probability

According to a report from a business intelligence​ company, smartphone owners are using an average of...

According to a report from a business intelligence​ company, smartphone owners are using an average of 23 apps per month. Assume that number of apps used per month by smartphone owners is normally distributed and that the standard deviation is 4. Complete parts​ (a) through​ (d) below.

A) If you select a random sample of 36 smartphone​ owners, what is the probability that the sample mean is between 22.5and 23.5?

B) If you select a random sample of 36 smartphone​ owners, what is the probability that the sample mean is between 22 and 23

C) If you select a random sample of 100 smartphone​ owners, what is the probability that the sample mean is between 22.5 and 23.5​?

In: Statistics and Probability

Seventy-one successes were observed in a random sample of n = 120 observations from a binomial...

Seventy-one successes were observed in a random sample of

n = 120

observations from a binomial population. You wish to show that

p > 0.5.

State the null and alternative hypothesis.

H0: p ≠ 0.5 versus Ha: p = 0.5H0: p < 0.5 versus Ha: p > 0.5     H0: p = 0.5 versus Ha: p ≠ 0.5H0: p = 0.5 versus Ha: p > 0.5H0: p = 0.5 versus Ha: p < 0.5

Calculate the appropriate test statistic. (Round your answer to two decimal places.)

z =

Provide an α = 0.05 rejection region. (Round your answer to two decimal places. If the test is one-tailed, enter NONE for the unused region.)

z> z<

State your conclusion.

H0 is rejected. There is insufficient evidence to indicate that p is greater than 0.5.H0 is not rejected. There is insufficient evidence to indicate that p is greater than 0.5.     H0 is not rejected. There is sufficient evidence to indicate that p is greater than 0.5.H0 is rejected. There is sufficient evidence to indicate that p is greater than 0.5.

In: Statistics and Probability

Thank you for your response to my first question. COULD YOU PLEASE ASSIGN SOMEONE ELSE TO...

Thank you for your response to my first question.

COULD YOU PLEASE ASSIGN SOMEONE ELSE TO HELP ME?

I HAVE BEEN ASKING FOR HELP FOR SEVERAL HOURS. THIS IS A FICTITIOUS STUDY. ALL OF THE INFORMATION THAT I WAS GIVEN IS BELOW. PLEASE READ IT.

For part #2, when comparing gender, GPA, and GRE test scores, would the statistical analysis be a one-way Anova, a two-way Anova, or a different test?.(See complete assignment below.)

Using this information, develop the following foundational components for a proposed analysis:

  1. A relationship research question involving GPA and GRE scores; corresponding null and alternative hypotheses; the type of statistical analysis to be employed to determine significance; explanations of fictitious outcomes identifying both non-significant and significant relationships as related to both null and alternative hypotheses; and recommendations based on non-significant and significant findings.
  2. A relationship research question involving gender, GPA, and GRE scores; corresponding null and alternative hypotheses; the type of statistical analysis to be employed to determine significance; explanations of fictitious outcomes identifying both non-significant and significant relationships as related to both null and alternative hypotheses; and recommendations based on non-significant and significant findings.
  3. An effect research question involving gender and GRE scores; corresponding null and alternative hypotheses; the type of statistical analysis to be employed to determine significance; explanations of fictitious outcomes identifying both a non-significant and a significant effect as related to both null and alternative hypotheses; and recommendations based on non-significant and significant findings.
  4. An effect research question involving gender, GRE score, and degree completion frequency; corresponding null and alternative hypotheses; the type of statistical analysis to be employed to determine significance; explanations of fictitious outcomes identifying both a non-significant and a significant effect as related to both null and alternative hypotheses; and recommendations based on non-significant and significant findings.
  5. Finalize your report with a written analysis of your results and recommendations for the dean based on your findings.

I have added the entire assignment. I am working on #2.
I have included the information and my question. It is in bold lettering.

In: Statistics and Probability

Sales of floor cleaners at Lavoie's Flooring Co. over the past 13 months are as follows:...

Sales of floor cleaners at Lavoie's Flooring Co. over the past 13 months are as follows:

Sales of floor cleaners -Lavoie's Flooring Co.  
Month Sale ($1,000s) Total 3 Months 3 Months Avg.
January 11
February 14 41 13.66666667
March 16 40 13.33333333
April 10 41 13.66666667
May 15 42 14
June 17 43 14.33333333
July 11 42 14
August 14 42 14
September 17 43 14.33333333
October 12 43 14.33333333
November 14 42 14
December 16 41 13.66666667
January 11 27 9
February ? 11

3.666666667

A. Using a moving average with three periods, determine the demand for floor cleaners for next February.

Answer: When using a moving average with three periods, we can determine the demand for floor cleaner in the next February is 3.6

B. Using a weighted moving average with three periods, determine the demand for floor cleaners for February.

Use 4, 2, and 1 for the weights of the most recent, second most recent, and third most recent periods, respectively. For example, if you were forecasting the demand for February, November would have a weight of 1, December would  have a weight of 2, and January would have a weight of 4.

Answer:

November 14 14*1 = 14 Forcast Fabruary = (14*1)+(16*2)+(11*4) / 4+2+1
December 16 16*2 = 32 90/7= 12.857
January 11 11*4 = 44
February ?

C. Use a trend analysis to forecast the demand for floor cleaners.

Answer: ?

D. Evaluate and compare the accuracy of each of these methods using at least one of the forecast error measures.

Answer: ?

F. Are all of the models used in parts a - c appropriate to use with the data provided? Why?

Answer: ?

In: Statistics and Probability

Discuss the strengths and weaknesses of correlational and regression studies; discuss concepts such as positive and...

Discuss the strengths and weaknesses of correlational and regression studies; discuss concepts such as positive and negative correlations, correlation coefficients, confounding, and causality.

In: Statistics and Probability

The ages of the members of a legislature from a particular state are listed below. Find...

The ages of the members of a legislature from a particular state are listed below. Find the​ mean, median, and mode of the data​ set, if possible.

61, 41 ,38,44,55,44,36,57,48

Find the mean age. Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice.

A.The mean age is

​(Round to one decimal place as​ needed.)

B.

There is no mean age.

The median age is.

​(Round to one decimal place as​ needed.)

B.

There is no median age.

Find the mode of the ages. Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice.

A.The​ mode(s) of the ages is​ (are)

​(Round to one decimal place as needed. Use a comma to separate answers as​ needed.)

B.

There is no mode.

In: Statistics and Probability

At the Bank of California, past data show that 19% of all credit card holders default...

At the Bank of California, past data show that 19% of all credit card holders default at some time in their lives. On one recent day, this bank issued 11 credit cards to new customers. Find the probability that of these 11 customers at most 3 credit card holders will default.

In: Statistics and Probability

The Central Limit Theorem is sufficiently accurate for individual observations when Poisson: min{yi} ≥ 3 Can...

The Central Limit Theorem is sufficiently accurate for individual observations when

Poisson: min{yi} ≥ 3

Can someone explain to me what this means? How do we find min{yi}?

In: Statistics and Probability