Directions: Use the Crosstabs option in the Descriptives menu to answer the questions based on the following scenario. (Be sure to select Chi-square from the Statistics submenu and Observed, Expected, Row, and Column in the Cells submenu. Assume a level of significance of .05) The school district recently adopted the use of e-textbooks, and the superintendent is interested in determining the level of satisfaction with e-textbooks among students and if there is a relationship between the level of satisfaction and student classification. The superintendent selected a sample of students from one high school and asked them how satisfied they were with the use of e-textbooks.

The data that were collected are presented

Student Classification (N = 128)

Satisfied Yes Freshman 20; Sophomore 21; Junior 11; Senior 13

No Freshman 11: Sophomore 7; Junior 23; Senior 22

1. Of the students that were satisfied, what percent were Freshmen, Sophomore, Junior, and Senior? (Round your final answer to 1 decimal place).

2. State an appropriate null hypothesis for this analysis.

3. What is the value of the chi-square statistic?

4. What are the reported degrees of freedom?

5. What is the reported level of significance?

6. Based on the results of the chi-square test of independence, is there an association between e-textbook satisfaction and academic classification?

7. Present the results as they might appear in an article.

3. It is frequently difficult for graduate schools to compare students from different undergraduate programs since universities have vastly different scales of assessment. Some schools, for example, are known to in ate grades while others maintain more rigorous grading standards. Say that you are a graduate school admissions officer charged with selecting those applicants that have the best undergraduate grades relative to their peers. You must decide between two students - one from Princeton and one from Temple. The Princeton student has a 3.9 grade point average (GPA), and the Temple student has a 3.4 average (GPA). At Princeton, the mean GPA is 3.65 with a standard deviation of .3, while at Temple the mean GPA is 3.15 with a standard deviation of .27. At both schools, GPAs are Normally distributed. Answer the following questions, and show how you arrived at these conclusions. (14 points)

a. If you are interested in selecting the student with the better record compared to the other students at his/her university, which student do you select and why? Make sure to back up your decision with evidence produced by your quantitative toolkit so that you're able to compare both students despite the fact that their schools are quite different.

b. What proportion of Temple students have a higher GPA than this Temple student (who is applying to graduate school in the above problem)?

The Gourmand Cooking School runs short cooking courses at its small campus. Management has identified two cost drivers it uses in its budgeting and performance reports—the number of courses and the total number of students. For example, the school might run two courses in a month and have a total of 64 students enrolled in those two courses. Data concerning the company’s cost formulas appear below:

For example, administrative expenses should be $4,000 per month plus $44 per course plus $5 per student. The company’s sales should average $870 per student.

The company planned to run four courses with a total of 64 students; however, it actually ran four courses with a total of only 60 students. The actual operating results for September appear below:

Required:

1. Prepare the company’s planning budget for September.

2. Prepare the company’s flexible budget for September.

3. Calculate the revenue and spending variances for September.

The administration at a university is interested in studying if any relationship exists between quality of academic experience at the school and whether the student is a major in the College of Humanities and Social Sciences (HSS major) or has a major in the College of Business (Business major). The school randomly surveys 10 seniors who are HSS students and 10 seniors who are Business students and asks them to rate the quality of their academic experience on a scale of 1-10, where 10 is extremely high and 1 is extremely low. Here are the data:

The HSS majors have a mean of 7.5 and a variance of 3.6, whereas the Business majors have a mean of 6.5 and a variance of 2.9.

Answer the following questions:

1. What is the null hypothesis? (1 point)

2. What is the research hypothesis? (1 point)

3. What is the dependent variable? (1 point)

4. Write out the results of an independent samples t-test using these data. In other words, provide the numerical answers: t-statistic, your critical value of t (or p-value), and degrees of freedom. (4 points)

5. Write a paragraph to explain the results of the hypothesis test using statistics from the problem with alpha=0.05. This should be two or more formal sentences to describe your findings and conclusions.

1a. A study of 24 randomly chosen dishwashers in Lincoln finds that the mean repair cost is $92.04, with a sample standard deviation of $12.26. Repair costs are known to be normally distributed. Find a 99% confidence interval for the mean repair cost of all dishwashers in Lincoln. Round the confidence interval values to the same number of decimal places as the sample mean.

1b. In a survey of 240 randomly selected high school wrestlers, 50 were injured during their junior year. Find a 90% confidence interval for the proportion of all high school wrestlers injured during their junior year. Round all proportions to 3 decimal places.

2. Choose ONE of the confidence intervals you found in #1. Write a sentence that gives the practical interpretation of that confidence interval.

3. A quality control inspector claims that over 10% of microwaves need repairs during the first five years of use. A researcher is testing this claim.

a. Write the null and alternative hypotheses, and tell whether the test is left-tailed, right-tailed, or two-tailed.

b. In a random sample of 114 microwaves, 16 needed repairs during the first five years. Find the test statistic.

c. Find the P-value.

d. The level of significance for this hypothesis test is 0.05. Should the researcher reject the null hypothesis or fail to reject the null hypothesis?

e. Write a conclusion in the context of the quality control inspector’s claim about microwaves.

The Weschler Intelligence Scale for Children (WISC) is an intelligence test designed for children between the ages of 6 and 16. The test is standardized so that the mean score for all children is 100 and the standard deviation is 15.

Suppose that the administrators of a very large and competitive school district wish to estimate the mean WISC score for all students enrolled in their programs for gifted and talented children. They obtained a random sample of 40 students currently enrolled in at least one program for gifted and talented children. The test scores for this sample are as follows:

106,142,110,123,135,114,119,118,121,95,154,119,109,131,130,98,117,105,143,94,106,142,110,123,135,114,119,118,121,95,154,119,109,131,130,98,117,105,143,94,

110,167,117,98,125,133,122,98,116,126,127,114,124,134,133,102,125,109,124,109110,167,117,98,125,133,122,98,116,126,127,114,124,134,133,102,125,109,124,109

Click to download the data in your preferred format.  

CrunchIt!    CSV   Excel   JMP   Mac Text    Minitab   PC Text   R   SPSS   TI Calc  

Use this data to calculate the mean WISC score,x¯, for these 40 students. Next, compute the standard deviation, SD, of the sampling distribution of the sample mean, assuming that the standard deviation of WISC scores for students in the district is the same as for the population as a whole. Finally, determine both the lower and upper limits of a 95% ?-confidence interval for μ, the mean score for all students in the school district who are enrolled in gifted and talented programs.

Give x¯ and the limits of the confidence interval precise to one decimal place, but give the standard deviation to at least three decimal places in order avoid rounding errors when computing the limits.

x¯=

SD =

Lower limit =

Upper limit =

1. Below are several research scenarios. Indicate which set of statistical analyses should be used to analyze the data collected in study, and explain why that statistical test should be used

(a) Teachers at a local middle school were interested in exploring the effects of a collaborative peer teaching program on the motivation levels of seventh-grade students. Four of eight classes of seventh grade students were randomly selected at Bulloch Middle School to serve as subjects in this study. Students within each class were then randomly assigned to one of three groups: a collaborative peer teaching program, group learning activities, or individual learning activities. Each class was taught by a different teacher. The Middleman motivation scale was used to measure motivation in the subjects, and this scale produces scores that range from 1 to 25 with higher scores indicating greater motivation. Validity for the Middleman scale was previously ascertained by examining how scores from the Middleman motivation scale corresponded to scores from variables that are theoretically related to motivation, such as effort to achieve, persistence, intelligence, and self-efficacy. Internal consistency for scores from the Middleman scale typically range between .81 and .86. Data for the current study were collected at the end of a 16 week program. Analysis of these data revealed that students in the individual learning activities demonstrated a statistically higher level of motivation compared with students in the two other, traditional groups .

1) Which of the following would be the best example of a public good?

a) Clean water at the public lake.

b) A community park.

c) Snowplowing the streets.

d) Public school.

2) Which of the following is the best example of a public good with exclusion?

a) A fireworks display that can be seen miles away.

b) Fire protection services offered by the city.

c) Satellite radio service.

d) A public lake.

3) Which of the following best represents a tragedy of the commons?

a) A shopping mall with no shoppers inside.

b) A severe traffic jam on the freeway.

c) A fire that burns an entire apartment complex.

d) A ski resort that has closed due to lack of snow.

4) Which of the following represents the best example of a free-rider?

a) Your roommate asking you for a ride to school but will not help out with gas.

b) A panhandler who sneaks onto the subway without paying.

c) A person without health insurance visiting an emergency room since they cannot be turned away.

d) A neighbor who plants vegetables in her garden and allows others to help themselves to her harvest.

5) Generally, the amount of public goods available in a society is _____ what is actually desired.

a) greater than

b) less than

c) exactly

d) either exactly or greater than

Please answer all of the questions and explain each answer!

Thank you.

The Gourmand Cooking School runs short cooking courses at its small campus. Management has identified two cost drivers it uses in its budgeting and performance reports—the number of courses and the total number of students. For example, the school might run two courses in a month and have a total of 60 students enrolled in those two courses. Data concerning the company’s cost formulas appear below:

For example, administrative expenses should be $3,800 per month plus $42 per course plus $5 per student. The company’s sales should average $880 per student.

The company planned to run four courses with a total of 60 students; however, it actually ran four courses with a total of only 56 students. The actual operating results for September appear below:

Required:

1. Prepare the company’s planning budget for September.

2. Prepare the company’s flexible budget for September.

3. Calculate the revenue and spending variances for September.

The Gourmand Cooking School runs short cooking courses at its small campus. Management has identified two cost drivers it uses in its budgeting and performance reports—the number of courses and the total number of students. For example, the school might run two courses in a month and have a total of 60 students enrolled in those two courses. Data concerning the company’s cost formulas appear below:

For example, administrative expenses should be $3,800 per month plus $42 per course plus $5 per student. The company’s sales should average $880 per student.

The company planned to run four courses with a total of 60 students; however, it actually ran four courses with a total of only 56 students. The actual operating results for September appear below:

Required:

1. Prepare the company’s planning budget for September.

2. Prepare the company’s flexible budget for September.

3. Calculate the revenue and spending variances for September.