2301 Final Exam Workbook Essay

In a laboratory study of sleep deprivation, researchers employed a variety of techniques to keep volunteers awake for variable amounts of time. One group of participants was kept awake for 24 hours, and the other was kept awake for 48 hours. During periods of forced wakefulness, participants were required to engage verbal learning tasks such as memorizing the definitions of obscure English words. At the conclusion of the period of forced wakefulness, participants were allowed to sleep for as

-3 x 1.66 pts. = minus 5 pts. = 45 pts. out of 50 pts. = 90%

12. _____ For a given population, confidence intervals constructed from larger samples tend to be narrower than those constructed from smaller samples. Which statement below best describes why this is true? (A) The variability of the sample mean is less for larger samples. (B) The z-value for larger samples tends to be more accurate. (C) The population variance is larger for large populations. (D) As the sample size increases, the z-value (or t-value) becomes smaller. A machine dispenses potato chips into bags that are advertised as containing one pound of product. To be on the safe side, the machine is supposed to be calibrated to dispense 16.07 ounces per bag, and from long time observation, the distribution of the fill-weights is known to be approximately normal and the process is known to have a standard deviation of 0.15 ounces.

Explain how you would enforce the data constraint that HW7G_ORDER_ITEM.UnitPrice be equal to HW7G_SERVICE.UnitPrice, where HW7G_ORDER_ITEM.Service = HW7G_SERVICE.Service. Again, no code at this time, just an explanation.

Explain each sampling technique discussed in the “Visual Learner: Statistics” in your own words, and give examples of when each technique would be appropriate.

I chose (c) for the answer as I thought that since both schools took the same percentage size of about 3% of the undergraduates and both had a proportion, p= 0.80, Johns Hopkins and Ohio State would have almost the same sampling variability. I forgot to take into account that each school had different numbers of undergraduates. However, the correct answer is (b). Since a simple random sample of about 3% of Ohio State is about (0.03 x 40,00) = 1,200, it has a larger sample than the (0.03 x 2,000) = 60 undergraduates that make up the simple random sample of about 3% of the undergraduates at Johns Hopkin, meaning Ohio State has smaller variability. Thus, the estimate from Johns Hopkins has more sampling variability than that from Ohio State since it has a smaller sample of 60 undergraduates, making

In this study, it uses surveys to analyze 135 seabirds to find that today about 90 seabirds have traces of plastic in their stomachs. A survey is what allows us to ask/study large numbers or people (in this case seabirds) questions about attitude and behavior (textbook p.44). The sample size for this specific study would be 135 which is the subset of a population being studied. The population in this case would be all seabirds, which is the entire group from which the sample was taken

A) The sample is the 100 students that took the survey and the population are the students at the school.

The project will be a multi-year phased approach to have all sites (except JV and SA) on the same hardware and software platforms.

Describe the sample. How does this sample represent the population? What makes a sample strong or weak? Evaluate this sample.

You plan to draw a sample of 60 students. Which of the following procedures will give you a simple random sample A) You assume that students have been randomly placed in classes, so you choose three classes by random selection and place all of those students in your sample. B) You have a list with the names of all the students on it. You choose one out of the first 10 names at random. Then you choose every nth student name on the list until you have 60 students for your sample. C) Choose the first 60 students that pass through the front door at the beginning of school in the morning. D) Put the name of each classmate in school on a piece of paper and place the pieces of paper in a cardboard box. Next randomly select 60 pieces of paper from the box. E) You randomly choose 10 students from each of

When conducting a study, it is impossible to collect data from the whole population, therefore it is important to select a representative sample because sampling makes it possible to select a representative for study and discover things that apply to many more people who are not studies (Maxfield & Babbie, 2012). The purpose of sampling is to generate a set of individuals or other entitles that give us a valid picture of all such individual or other entitles. It is important to generalise from a sample to unobserved population the sample in intended to represent. Therefore, when selecting a group of subjects for study, it is important to ensure that we represent some larger population.

All of these examples of collecting and conducting data will have to involve using samples conducted by the population and applying inferential information, which is obtained through representatives. These samples are typically those possessed by the population of interest when conducting a sample population by choosing random samples of every different sample size. It gives them an equal chance of selection and does not target those that would compromise the data.

Through what means would you extract a representative sample from the total population? Describe your procedure.

a. The way you can gain access to the Official SAT Question of the Day is