Survey for students of Jon Anderson

Part I: Questionnaire

1. In what year did you last take STAT 1601?

2000 2001 2002 2003 2004 2005 2006 2007

2. In what semester did you last take STAT 1601?

Fall Spring Summer

3. Please list how many courses in statistics you took prior to STAT 1601?

0 1 2 3 4 5 6 7 8 9 10+

4. How many courses in statistics have you had since STAT 1601?

5. Have you read any books on statistics or done any other outside learning that might have increased your knowledge of statistics substantially beyond what you learned in STAT 1601? Please check the option that best corresponds to your level of outside learning.

No outside learning Minimal outside learning Some outside learning Extensive outside learning

6. How many hours per week were you tutored on average during your STAT 1601 class?

7. Please check off each item below that corresponds to a teaching method your professor used in the course. You can choose more than one.

Textbook Additional readings beyond the textbook Worksheets Overheads presented in class PowerPoint or other computer slides presented in class Professor made notes available online Videos Learning activities involving designing an experiment or study Learning activities involving analyzing a dataset and writing a report Learning activities involving giving an in-class presentation Peer tutoring Use of specialized statistical software (SPSS, Sysstat, etc.) If your professor used a method not listed here, please describe it in the box:

8a. Can you recall any specific experiences during your STAT 1601 course that were particularly memorable? If so please briefly describe as many as you can. Write your response in the box below.

8b. How many separate memories did you list?

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

For the next two questions, please mark the response that indicates the extent to which you agree with the statement:

9. I was able to completely master the skills and knowledge taught to me in STAT 1601

Strongly Disagree Disagree Somewhat Disagree Somewhat Agree Agree Strongly Agree

10. My STAT 1601 course was personalized to fit my needs.

11. Please mark the option that best describes your studying habits during STAT 1601:

Studied multiple days each week Mostly studied on nights before an exam

12. Please indicate your personal level of interest in statistics

13. Please indicate the degree to which you consider knowledge of statistics relevant to your future career plans.

Very Irrelevant Irrelevant Somewhat Irrelevant Somewhat Relevant Relevant Very Relevant

14. What is your class standing? Please choose one.

Freshman Sophomore Junior Senior Graduate

15. What is your gender?

Male Female

16. Please list your majors and minors.

1st major:

2nd major:

3rd major:

1st minor:

2nd minor:

3nd minor:

17. What is your age? Please choose one.

Younger than 18. 19-20 21-24 25 or older.

18. What is your student ID number? (This number will only be used by your professor to access your original exam scores and grades from STAT 1601 and will be erased thereafter. No one except your professor will know what name or ID number goes with what original exam scores or grades.)

Please enter numbers only

Part II: Test

Instructions: You will need a piece of scratch paper to work on. You may use a calculator but please do not use any other outside help that you did not have during the original exam. Providing a good but honest effort will help the statistics department accurately assess learning and identify areas that need improvement.

Table of normal probabilities:

Read each question carefully before selecting the best answer. You will need to use the above table to answer some questions.

For questions 1-3 use the following information: According to advertisements, a strain of soybeans planted with a specified fertilizer treatment has a mean yield of 500 bushels per acre. Fifty farmers plant the soybeans. Each farmer has a 40-acre plot and records the average yield per acre. The sample mean is 485 and the sample standard deviation is 100.22. The data appear to be normally distributed. Do the data provide sufficient evidence to indicate that the mean yield for the soybeans is different from that advertised?

1. What are the most appropriate null and alternative hypotheses for this problem? (a) H0 : mean of x = 485, Ha : mean of x = 485 (b) H0 : μ = 485, Ha : μ = 485 (c) H0 : μ = 500, Ha : μ = 500 (d) H0 : p = 485, Ha : p > 485

2. What is the value of the test statistic for testing the null hypothesis of no difference from the advertised amount? (a) 0.1496 (b) -1.058 (c) -0.1496 (d) 1.058 3. Suppose that the p-value for this problem is .25. Which of the following statements BEST describes the final conclusion for this problem?

(a) There is evidence against the alternative hypothesis. (b) There is evidence that the mean yield differs from 500. (c) There is no evidence that the mean yield differs from 485. (d) There is evidence that the mean yield is 500. (e) There is evidence that the mean yield differs from 485. (f) There is no evidence that the mean yield differs from 500. For question 4-5, use the following information: The table given below gives the results of giving steroid tests to 1000 male athletes in 1995 and 500 male athletes in 2005 selected randomly for testing.

4. What is the probability that a person tests positive for steroids given that they are tested in 1995? (a) .25 (b) .75 (c) .15 (d) .10 5. What is the probability a person is tested in 2005 given they test negative for steroids?

(a) .900 (b) .867 (c) .654 (d) .346 Use the information below to answer questions 6-7. The payoff X of a gambling game has the probability distribution given below. Assume the units of X are in dollars.

6. What is the mean or expected payoff, E[X] for playing this game? (a) 1.0 dollar (b) 0.90 dollars (c) 0.70 dollars (d) 0.30 dollars 7. What is the probability that you will come out behind (lose money) by playing the game twice if the game costs $1 per play? (a) .81 (b) .01 (c) .90 (d) .19

For questions 8-9 please use the following information. In a large midwestern city, a random sample of 395 homes on the resale market showed 32 homes were on the market because of a mortgage default.

8. Find a 90% confidence interval for the parameter p, the proportion of all homes on the resale market due to mortgage default.

(a) (.325, .473) (b) (.054, .108) (c) (.004, .031) (d) (.058, .104) (e) (.063, .098)

9. In the past few years 13% of homes on the resale market were due to mortgage default. Do we have evidence that the proportion of such homes on the market has decreased this year? Choose the best answer.

(a) No (b) Yes (c) It is not conclusive evidence. Use the following information for problems 10-11: A toy manufacturer thinks red should be the color for the new toy 4-wheel drive pickup truck. Blue is the other color possibility being considered. An experiment is conducted on 100 randomly selected children, and the number that prefer the red truck is recorded. The statistician hired by the toy company decides to use a hypothesis test involving the population parameter p, the proportion of children that prefer the red color in the population.

10. Suppose the most appropriate hypothesis test for this problem is, H0 : p = .5 vs Ha : p = .5. Also suppose the test statistic value for this problem is 2.29. What is the correct p-value for this problem?

(a) .9890 (b) .0110 (c) .0113 (d) .0220 11. For the same toy truck situation, let’s suppose the p-value for the hypothesis test described in question 10 was .37. Which of the following choices is the best conclusion for this problem? (a) There is evidence to doubt the null hypothesis. (b) There is evidence to support the null hypothesis. (c) There is evidence red is preferred. (d) There is no evidence red is preferred.

12. It is known that when a machine that dispenses cola into bottles on an assembly line is working correctly, it dispenses with a mean μ = 12 ounces and a standard deviation σ = .2 ounces. The distribution of dispensed values is approximately a normal distribution. What proportion of the time will a correctly operating machine dispense between 11.4 and 12.6 ounces? Choose the best answer.

(a) .9500 (b) .9974 (c) .9734 (d) .0026 13. There are 8 seats on a plane, and the probability of a ticket holder showing up for the flight is .5. Assume 8 tickets are sold. Find the probability that more than 6 ticketholders show up for the flight?

(a) .9500 (b) .9974 (c) .9734 (d) .0026

Use the information given below to answer questions 14-16. A study in the journal Physical Therapy (Feb 1991), discusses range-of-motion measurements on patients with knee complaints. One measurement taken was height (in centimeters) of the patients. The mean height was 170.8 cm and the standard deviation was 10.5 cm. If the height of such patients is normally distributed with mean μ = 170.8 and standard deviation σ = 10.5, answer the following questions. 14. What proportion of such patients would exceed 180 cm in height?

(a) .1922 (b) .8106 (c) .8078 (d) .1894 15. What is the probability that the average height of a sample of 16 such patients will exceed 190cm?

(a) Probability > .9998 (b) Probability < .0001 (c) .3707 (d) .0228

16. What is the 80th percentile of the height distribution in this population?

(a) 179.62 cm (b) 179.20 cm (c) 161.98 cm (d) 184.24 cm The following stem and leaf display (stemplot) should be used to answer questions 17-18. The smallest observation is 30. 3 01113 4 125556 5 078899 6 26679 7 58

17. The median is?

(a) 50 (b) 53.5 (c) 47.5 (d) 51.8

18. For the same data as in question 17, from simply looking at the display above and doing no computations, which of the following values is the most reasonable value for the standard deviation of this data list?

(a) 3 (b) 5 (c) 11 (d) 48 19. Suppose you were analyzing the teaching evaluations for a faculty member on a question with a five point scale with 3 meaning satisfactory. Values below 3 indicate less than satisfactory performance and values above 3 indicate above satisfactory performance. Suppose a 95 percent confidence interval for the average rating was (2.2, 2.7). Circle the most appropriate conclusion.

(a) There is evidence of satisfactory performance. (b) There is evidence of above satisfactory performance. (c) There is evidence that the performance is significantly different from satisfactory. (d) There is no evidence that the average performance is different than satisfactory. (e) There is evidence of below satisfactory performance.

Use the following for questions 20-21. A new variety of apple is meant to resist disease. A scientist grows 50 trees of the new strain and 100 of the parent strain under the same field conditions. In 3 years, each tree is classified as ”seriously infected” or ”not seriously infected” by the disease. It found 25 trees of the new strain and 69 of the parent strain are seriously infected. Suppose we wish to do a hypothesis test to determine if there is evidence to suggest that the new strain of apple is more resistant to disease than the old one.

20. What is the correct null hypothesis for this problem?

(a) pn − pp = 0 (b) pn > pp (c) pn < pp (d) pn = pp

21. What is the value of the test statistic for this test?

(a) Test statistic less than 1.0 in absolute value. (b) Test statistic more than 1.0 in absolute value. 22. Suppose we wish to study governmental structures at the county level in the USA. We need to have a random sample of USA counties. We first take a simple random sample of 10 states from the list of states. From each selected state, we place counties in that state on a list. Then a random sample of 6 counties is selected from the list. This is repeated for each of the 10 selected states. What sampling design was used?

(a) Stratified Sampling (b) Simple Random Sampling (c) Multi-Stage Sampling (d) Convenience Sampling 23. A psychological test is used to measure academic motivation. The average test score for all female college students is 115. A large university estimates the mean test score for female students on its campus by testing a random sample of n female students and constructing a confidence interval based on their scores. Which of the following about the confidence interval are true? 1. The resulting interval will contain the mean of x. 2. The 95% confidence interval for n = 100 will generally be shorter than the 95% confidence interval for n = 50. 3. For n = 100, the 95% confidence interval will be longer than the 90% confidence interval.

(a) 2 only (b) 3 only (c) None of the statements 1,2, 3 are true. (d) All of the statements 1,2,3 are true. (e) 2 and 3

24. When performing a test of significance for a null hypothesis, Ho, against an alternative hypothesis, Ha, a big p-value means

(a) it is likely the Ho is true. (b) it is likely the Ha is true. (c) it is likely the Ha is false. (d) the data are consistent with the Ha. (e) None of the above. 25. The GPA (on a scale of 1-5) of a sample of students at an East-Coast University has sample mean 3.9106 and sample standard deviation 0.256, with 95% confidence interval (3.488,4.333). Which of the following is correct? (a) There’s a 95% chance that the true mean falls between 3.488 and 4.333. (b) The estimate is within 95% of the true mean. (c) The population has a normal distribution with mean 3.9106 and standard deviation 0.256. (d) If we sample many times, the proportion of intervals computed that cover the true mean is about 95%. 26. Suppose that someday a local bar hires a local microbrewer to make good beer for them to serve at their bar. As part of the quality control efforts, you are hired to determine if bottles are filled appropriately to the stated amount on the label. Suppose you compute a 95 percent confidence interval for the average amount in the bottles. The microbrewer gives you 11 bottle measurements to use in your confidence interval computation. What formula will you use to do your confidence interval?

(a) mean of x ± Z(σ/√n) (b) mean of x ± T(σ/√n) (c) mean of x ± Z(s/√n) (d) mean of x ± T(s/√n) Use the following description for questions 27-30. A bacteriologist grows C. botulinum in a clear culture. As the experiment progresses, she measures how much the colony has grown by measuring the optical density of the solution with a photometer. The solution gets darker as the colony grows. A scatterplot of the data is given below. Time is measured in hours and density is the photometer reading measured in photometer units. Use the output on the next page to answer the following questions: 27. What is the typical distance from a point to the least squares line?

(a) 13.40 (b) 18.19 (c) 24.50 (d) 24.47

The estimated regression equation is:

density = 18.2 + 24.5*time

s = estimate of sigma = 13.40

R-squared = 93.2%

28. If a new measurement is added at x = 6 hours and density y = 60, what will happen to the estimated slope coefficient?

(a) The estimate will be greater than 18.2. (b) The estimate will be less than 18.2. (c) The estimate will be less than 24.5. (d) The estimate will be greater than 24.5. 29. From the output, give an estimate for what the density of the colony was after one hour.

(a) 44.25 units (b) 75.34 units (c) 9.98 units (d) 42.66 units

30. From the output, give an interpretation of the estimated slope coefficient.

(a) As density increases, time increases by 24.5 hours. (b) As time increases, density increases by 18.2 units. (c) As time increases, density increases by 13.4 units. (d) As time increases, density increases by 24.5 units. (e) As density increases, time increases by 24.5 units.

Use the following information for 31. In an experiment designed to compare the effectiveness of two methods of teaching French, 20 students were randomly assigned to each of the two methods. The scores on a final exam are to be compared. A summary of the results is given here. For method A n = 20, ¯x = 82, and s = 14. For method B, n = 20, ¯x = 78, s = 15. The observations appear to be normally distributed in both groups. Perform a hypothesis test to determine if there is evidence for a difference in learning between the two teaching methods. Give an appropriate conclusion. 31.

(a) There is evidence the methods differ in effectiveness. (b) There is no evidence the methods differ in effectiveness. (c) There is evidence method A is superior to method B. (d) There is evidence method B is superior to method A. (e) There is evidence the teaching methods have the same effectiveness.

32. Suppose we are interested if there is a difference in the proportion of people having a minor skin ailment cured with treatment A or treatment B. Suppose a 95% confidence interval for the proportion of people that are cured with treatment A minus the proportion cured with treatment B is (.1, .14). Give a complete conclusion based on this confidence interval.

(a) There is evidence the treatments differ in effectiveness. (b) There is no evidence the treatments differ in effectiveness. (c) There is evidence treatment A is superior to treatment B. (d) There is evidence treatment B is superior to treatment A. (e) There is evidence the treatments have the same effectiveness.

33 An experiment is being planned to study the effects of exercise and diet on cholesterol levels. There are 3 levels of exercise: low, moderate, high. There are 2 levels of diet: regular diet, regular diet with a fiber supplement. Each level of exercise is examined at each level of diet. How many factors are there in this experiment?

(a) Three (b) Two (c) Six (d) Nine 34 In a Statistics 1601 class survey I asked students to state the division of their intended major: science and math, education, social science, or humanities. I also asked if the student smoked or not. What statistical approach should be used to determine if there are differences in smoking proportions across the four academic divisions at UMM?

(a) One way ANOVA. (b) Two sample T test. (c) One sample T test. (d) Confidence interval for two proportions. (e) Chi-square analysis.

35. Several litters of piglets were used to examine two diets on growth. Two piglets of same sex were randomly selected from each litter. One piglet was randomly assigned diet A and the other was given diet B. After 10 weeks the amount grown was measured. How should researchers determine if there are differences in growth due to the diet? Suggest the statistical method to use.

(a) One way ANOVA (b) Two sample T confidence interval (c) Two sample test for proportions. (d) One sample T test.

17. What is your email address? (Entering this address verifies that you have participated in the study. It will only be used to contact you so we can make arrangements for you to receive your payment, it will not be connected to your class grades in any way.)

When you are finished, check your work and then hit SUBMIT below. If you need to start over, hit RESET to clear your answers.