La Salle University

SOC 301 Principles of Statistics Project 2 Assignment

*General Instructions*: All projects must be typed, but hand written normal curves and mathematical calculations are permitted.

SOC 301 Principles of Statistics Project 2 Assignment

- Using any data set available on Canvas or from the textbook, identify three variables – one that is measured at the
*nominal*level, one that is measured at the*ordinal*level and one that is measured at the*interval*For each variable, complete the following in sentence form:- Explain what the variable measures and the level of measurement.
- Report all appropriate descriptive statistics. (Please copy and paste your output table directly into your project at the space for #1.)
- Create an appropriate visual representation of the variable.

- Use the study description below to complete the following:
- Identify the independent and dependent variables.
- Identify the sample and the population.
- State the null hypothesis in sentence form.
- State the alternative hypothesis in sentence form.

SOC 301 Principles of Statistics Project 2 Assignment

*Prior research has found a relationship between hours of sleep and academic success. This study sought to contribute to this body of knowledge by using a sample of 1,500 college freshmen at a northeastern university. We anticipate that college freshmen who get more than six hours of sleep will be less likely to drop out after their first year of college. Findings will have implications for programs to encourage sleeping habits among all college students nationwide.*

- Congratulations! You have been given the magic wand of research! You can design any research study you would like without concern for feasibility or financial cost. Describe the study you would like to conduct. Be sure to complete the following:
- Identify the independent and dependent variables.
- Identify the sample and the population.
- State the null hypothesis in sentence form.
- State the alternative hypothesis in sentence form.

SOC 301 Principles of Statistics Project 2 Assignment

- The mean test score is 83 with a standard deviation of 5. Answer the questions below. (Be sure to show your work.)
- What is the probability that any given test score will be greater than 95?
- What is the probability that any given test score will be less than 70?
- What is the probability that any given test score will be between 65 and 90?
- In your own words, explain how the normal distribution allows you to determine these probabilities.

- A race horse named Speedy has an average race time of 45 seconds with a standard deviation of 4 seconds. Assuming that horse racing times compose a normal distribution, a gambler wants to know the range of times within which 99% of all Speedy’s races will fall. What is the range of race times within which 99% of all Speedy’s races will fall? (Be sure to show your work.)

- You’re at a county fair and come across a game with the spinner shown below. You get two spins and if you land on the same number twice, you win a stuffed animal. What’s the probability that you get the same number twice in two spins? Identify the rule(s) of probability used to reach your answer.

SOC 301 Principles of Statistics Project 2 Assignment

- The La Salle Admissions Office wants to study applying students’ impressions of La Salle’s campus, but they don’t have the resources to survey every student who has applied.
- Explain how the Admissions Office could use a convenience sample to investigate their research question. Be sure to clearly explain the steps used.
- Explain how the Admissions Office could use a probability sample to investigate their research question. Be sure to clearly explain the steps used.
- Explain the advantages and disadvantages of each type of sample.

- Explain what type of error Dr. Fred likely made in the scenario below:

Dr. Fred wants to study the relationship between alcoholism and liver disease. He hypothesizes that alcoholics will have higher rates of liver disease than non-alcoholics. In his sample of 30 people, he finds that 2% of the alcoholics have liver disease and 2% of the non-alcoholics have liver disease. He thus accepts the null hypothesis. Dr. Jane conducts the same exact study as Dr. Fred except she uses a sample size of 300 people. She finds that 25% of the alcoholics in her sample have liver disease compared to only 5% of the non-alcoholics. She thus rejects the null hypothesis.

SOC 301 Principles of Statistics Project 2 Assignment

- Assuming that test scores compose a normal distribution, calculate a 95% confidence interval for the following samples of test scores: (Be sure to show your work.)
- Mean = 77 and standard deviation = 5
- Mean = 88 and standard deviation = 3

- Assuming that test scores compose a normal distribution, calculate a 99% confidence interval for the following samples of test scores: (Be sure to show your work.)
- Mean = 43 and standard deviation = 8
- Mean = 25 and standard deviation = 15

SOC 301 Principles of Statistics Project 2 Assignment