A student researcher compares the heights of American students and non-American students from the student body of a certain college in order to estimate the difference in their mean heights. A random sample of 1818 American students had a mean height of 68.968.9 inches with a standard deviation of 2.712.71 inches. A random sample of 1212 non-American students had a mean height of 65.765.7 inches with a standard deviation of 2.172.17 inches. Determine the 90%90% confidence interval for the true mean difference between the mean height of the American students and the mean height of the non-American students. Assume that the population variances are equal and that the two populations are normally distributed.

Step 1 of 3: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Step 2 of 3: Find the standard error of the sampling distribution to be used in constructing the confidence interval. Round your answer to two decimal places.

Step 3 of 3: Construct the 90%90% confidence interval. Round your answers to two decimal places.

After surveying students at a​ college, a campus organization calculated that a​ 95% confidence interval for the mean cost of food for one term is​ ($1372, $1562). Now the organization is trying to write its report and is considering the following interpretations. Comment on each. Complete parts a through e below.

a) 95% of all students pay between​ $1372 and​ $1562 for food.

Comment on the given interpretation. Choose the correct answer below.

A. The interpretation is incorrect. A confidence interval estimates a sample parameter.

B. The interpretation is incorrect. A confidence interval is not about a population parameter.

C. The interpretation is incorrect. A confidence interval is not about individuals in the population.

D. The interpretation is correct. A confidence interval estimates a population parameter.

b) 95% of the students paid between $1372 and $1562.

c) We're 95% sure that students in this sample averaged between $1372, $1562 for food.

d) 95% of all samples of students will have average food costs between $1372 and $1562.

e) We're 95% sure that the average amount of all students pay between $1372 and $1562.

You believe that requiring students to attend a series of presentations on study skills will improve their grades. You are concerned that boys and girls might react differently to such a series, and that students in grades 9 and 10 might react differently than those in grades 11 and 12. You set up an experiment involving 100 students in ninth and tenth grade and 100 students in eleventh and twelfth grade. (Assume there are equal numbers of girls and boys in each grade.) You intend to measure improvement based on pre- and post-treatment grade-point averages.

Describe the design of an experiment to help you determine if a set of presentations on study skills is effective in improving grades.

Answer:

Suppose you have 50 students and need to assign them to two groups of equal size. Describe a randomization procedure that would achieve this.

Answer:

Suppose you have 50 students and need to assign them to two independent groups. Describe a randomization procedure that would achieve this.

Answer:

Describe an appropriate method of analysis for the data you collect from this experiment.

Answer:

A rich donor has approached a small liberal arts college and wants to know what the total of all of the student debt at the college is. She is considering paying off every student’s debt, but needs to know how much that is before she publicly announces her plan. In response, the school decides to conduct a survey of its students to find out what the total of all students’ debt is. They want to be sure that in-state, out-of-state, and international students are all properly represented so they decide to take a stratified sample. Using the below information, calculate the total student debt for the college and construct a confidence interval around the total student debt for the college. NOTE: You will have to choose a reasonable confidence interval.

Kenton and Denton Universities offer executive training courses to corporate clients. Kenton pays its instructors $5,382 per course taught. Denton pays its instructors $299 per student enrolled in the class. Both universities charge executives a $348 tuition fee per course attended.

Required

a.Prepare income statements for Kenton and Denton, assuming that 18 students attend a course.

b.Kenton University embarks on a strategy to entice students from Denton University by lowering its tuition to $228 per course. Prepare an income statement for Kenton assuming that the university is successful and enrolls 36 students in its course.

c.Denton University embarks on a strategy to entice students from Kenton University by lowering its tuition to $228 per course. Prepare an income statement for Denton, assuming that the university is successful and enrolls 36 students in its course.

e.Prepare income statements for Kenton and Denton Universities, assuming that 9 students attend a course, and assuming that both universities charge executives a $348 tuition fee per course attended.

You believe that requiring students to attend a series of presentations on study skills will improve their grades. You are concerned that boys and girls might react differently to such a series, and that students in grades 9 and 10 might react differently than those in grades 11 and 12. You set up an experiment involving 100 students in ninth and tenth grade and 100 students in eleventh and twelfth grade. (Assume there are equal numbers of girls and boys in each grade.) You intend to measure improvement based on pre- and post-treatment grade-point averages a.

a. Describe the design of an experiment to help you determine if a set of presentations on study skills is effective in improving grades.

b. Suppose you have 50 students and need to assign them to two groups of equal size. Describe a randomization procedure that would achieve this.

c. Suppose you have 50 students and need to assign them to two independent groups. Describe a randomization procedure that would achieve this.

d. Describe an appropriate method of analysis for the data you collect from this experiment.

You believe that requiring students to attend a series of presentations on study skills will improve their grades. You are concerned that boys and girls might react differently to such a series, and that students in grades 9 and 10 might react differently than those in grades 11 and 12. You set up an experiment involving 100 students in ninth and tenth grade and 100 students in eleventh and twelfth grade. (Assume there are equal numbers of girls and boys in each grade.) You intend to measure improvement based on pre- and post-treatment grade-point averages a.

a. Describe the design of an experiment to help you determine if a set of presentations on study skills is effective in improving grades.

b. Suppose you have 50 students and need to assign them to two groups of equal size. Describe a randomization procedure that would achieve this.

c. Suppose you have 50 students and need to assign them to two independent groups. Describe a randomization procedure that would achieve this.

d. Describe an appropriate method of analysis for the data you collect from this experiment.

In the past, 60 % of all undergraduate students enrolled at state university earned their degrees within four years of matriculation. a random sample of 95 students from the class that matriculated in the fall of 2012 was recently selected to test whether there has been a change in the proportion of students who graduate within four years. Administrators found that 40 of these 95 students graduated in the spring of 2016 (i,e. , four academic years after matriculation) .

a . given the sample outcome , calculate a 95 % confidence interval for the relevant population proportion . does this interval estimate suggest that there has been a change in the proportion of students who graduate within four years? why or why not ? Please do in excel

b. suppose now that state university administrators want to test the claim made by faculty that the proportion of students who graduate within four years at state university has fallen below the historical value of 60\% this year. use this sample proportion to test their claim . report a p -value and interpret it . Please do in excel

Kenton and Denton Universities offer executive training courses to corporate clients. Kenton pays its instructors $6,622 per course taught. Denton pays its instructors $301 per student enrolled in the class. Both universities charge executives a $349 tuition fee per course attended.

Required

1. Prepare income statements for Kenton and Denton, assuming that 22 students attend a course.

2. Kenton University embarks on a strategy to entice students from Denton University by lowering its tuition to $229 per course. Prepare an income statement for Kenton assuming that the university is successful and enrolls 44 students in its course.

3. Denton University embarks on a strategy to entice students from Kenton University by lowering its tuition to $229 per course. Prepare an income statement for Denton, assuming that the university is successful and enrolls 44 students in its course.

5. Prepare income statements for Kenton and Denton Universities, assuming that 11 students attend a course, and assuming that both universities charge executives a $349 tuition fee per course attended.

Two teaching methods and their effects on science test scores are being reviewed. A random sample of 16 16 students, taught in traditional lab sessions, had a mean test score of 80.8 80.8 with a standard deviation of 4.4 4.4 . A random sample of 14 14 students, taught using interactive simulation software, had a mean test score of 85.6 85.6 with a standard deviation of 5.1 5.1 . Do these results support the claim that the mean science test score is lower for students taught in traditional lab sessions than it is for students taught using interactive simulation software? Let μ1 μ 1 be the mean test score for the students taught in traditional lab sessions and μ2 μ 2 be the mean test score for students taught using interactive simulation software. Use a significance level of α=0.05 α = 0.05 for the test. Assume that the population variances are equal and that the two populations are normally distributed. Step 2 of 4 : Compute the value of the t test statistic. Round your answer to three decimal places.