In a study of the relationship between family size and school performance in junior high school, 25 children in “only child ” families had an average GPA (grade point average) of 2.82 with a standard deviation of 0.34, and 20 first-born children in two-child families had an average GPA of 2.96 with a standard deviation of 0.38. At the 0.05 level of significance, is the difference between these means significant?

1. You must state the null and alternative hypotheses.

2. Compute the test statistics and p-value.

3. State the decision and make the conclusion in the words of the problem.

The national mean annual salary for a school administrator is $90,000 a year. A school official took a sample of 25 school administrators in the state of Ohio to learn about salaries in that state to see if they differed from the national average. Click on the datafile logo to reference the data. (a) Choose the hypotheses that can be used to determine whether the population mean annual administrator salary in Ohio differs from the national mean of $90,000. H0: Ha: (b) The sample data for 25 Ohio administrators is contained in the file named Administrator. What is the p value for your hypothesis test in part (a)? If required, round your answer to four decimal places. Do not round your intermediate calculations. 0.0213

1. A high school guidance counselor is interested in the association between proximity to school and participation in extracurricular activities. He collects the following data on distance from home to school (in miles) and number of clubs joined for a sample of 10 students.

                        Student                 Miles to school        Number of clubs               

                        Lanny                         4                          3

                        JoJo                           2                          1

                        Twilla                          7                          5

                        Rerun                         1                          2

                        Ginny                         4                          1

                        Stevie                         6                          1

                        George                       9                         9

                        Ruth                           7                          6

                        Carol                          7                          5

                        Dave                         10                         8

1. Calculate the Pearson's correlation coefficient for the association between distance to school and number of clubs joined by these students. As always, make sure to show all of your work.
2. Provide an interpretation for the correlation coefficient, making sure to specify what the direction implies. For this problem, first interpret the magnitude of the correlation, then specify what it would mean for club membership if someone lived further from school. (Hint: You should do this for every correlation interpretation.)
3. Is the correlation statistically significant? Explain your answer, using a hypothesis test. There are two methods: 1) Comparing obtained r to critical r; 2) comparing obtained t to critical t. You should write out the research and null hypotheses in Greek notation.

In a large city school system with 20 elementary schools, the school board is considering the adoption of anew policy that would require elementary students to pass a test in order to be promoted to the next grade. The PTA wants to find out whether parents agree with this plan. Listed below are some of the ideas proposed for gathering data. For each, indicate what kind of sampling strategy is involved and what (if any) biases might result.

a. Put a big ad in the newspaper asking people to log their opinions on the PTA website.

b. Randomly select two of the elementary schools and contact every parent by phone.

c. Send a survey home with every students, and have parents fill it out and return it the next day. Assume all parents submitted a survey.

d. Randomly select 20 parents from each elementary school. Send them a survey, and follow up with a phone call if they do not return the survey within a week.

1. The role of slavery in the industrial revolution in the United States was so important to disregard, but management textbook usually say nothing about slavery.

1. Explain the used of slave in the development of industry in USA.
2. Discuss the methods used by the Robber Barons to hide their ugly business behaviours which harmed and suffered many people.
3. Explain the role of scientific management, founded by FW. Taylor in the development of industry in USA.
4. Explain why trade union refused the implementation of scientific management in industries.

Health and welfare professionals working in the community in which several of your clients live have decided to institute an after-school recreation program for teenagers. The county government is reluctant to appropriate funds, although school officials are eager to donate school sports facilities. Teenagers and their parents agree about the importance of an after-school program. Your objective is to develop a community-wide recreation program for teenagers. Based on Healthy People 2020, select the two best intervention activities for this objective and state the reasons for your choice. References should be included at the end of the answer and in a reference page for complete credit

Twenty years​ ago, 56​% of parents of children in high school felt it was a serious problem that high school students were not being taught enough math and science. A recent survey found that 295 of 750 parents of children in high school felt it was a serious problem that high school students were not being taught enough math and science. Do parents feel differently today than they did twenty years​ ago? Use the α=0.01 level of significance.

What are the null and alternative​ hypotheses?

H0​: _______versus H1​: _______

​(Type integers or decimals. Do not​ round.)

The table lists the number of students from three different high schools participating in the mathematics and physics sections of a science fair High School 1 High School 2 High School 3 Mathematics 7 7 18 Physics 37 17 21

Given the following results.

a) State the alternative hypothesis statement. (1 mark)

b) State the degrees of freedom. (1 mark)

c) Find the value of A, B, and C. d) Using the p-value method, at α = 0.05, test the claim that the section of participation and the high school where the students were from are independent.

A vehicle quality survey asked new owners a variety of questions about their recently purchased automobile. One question asked for the owner’s rating of the vehicle using categorical responses of average, outstanding, and exceptional. Another question asked for the owner’s education level with the categorical responses some high school, high school graduate, some college, and college graduate. The Excel Online file below contains the sample data for 500 owners who had recently purchased an automobile. Construct a spreadsheet to answer the following questions.

Observed Frequency Table

Expected Frequency Table

a. Use a .05 level of significance and a test of independence to determine if a new owner's vehicle quality rating is independent of the owner's education.

Compute the value of the  test statistic (to 2 decimals).

???????

The p-value is ????? (to 4 decimals).

What is your conclusion?

Cannot conclude that the quality rating is not independent of the education of the owner.

b. Use the overall percentage of average, outstanding, and exceptional ratings to comment upon how new owners rate the quality of their recently purchased automobiles.

Average: 27% (to whole number)

Outstanding: 47% (to whole number)

Exceptional: 26% (to whole number)

New owners appear to be satisfied with the recent purchase of their automobile. 73% (to whole number) of owners rated their automobile as Outstanding or Exceptional.