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Dataset below gives a picture of the first 15 values in a dataset that contains information on students within a particular university. Which are the variables (or ‘fields’) and which are the cases? Suggest two questions that we could possibly answer through an analysis of the data in dataset.

From the data given, the age of the students would be the variables since variables represent data that cannot be measured empirically. The cases would be the qualification entry requirements to the university since it is the subject matter of the analysis, and unlike the age of the students, it...

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Tutor O-Rama claims that their services will raise student SAT math scores at least 50 points. The average score on the math portion of the SAT is μ=350 and σ=35. The 100 students who completed the tutoring program had an average score of 385 points. Is the students’ average score of 385 points significant at the 5% and 1% levels to support Tutor O-Rama’s claim of at least a 50-point increase in the SAT score? Is the Tutor O-Rama students’ average score of 385 points significantly different at the 5% and 1% levels from the average score of 350 points on the math portion of the SAT? What conclusion can you make, based on your results, about the effectiveness of Tutor O-Rama’s tutoring?

a. The average score of 385 points should be compared to the score of 400 points, considering that the tutor claims that their services will increase the average score of 350 by at least 50. z = ((x-μ)/√(σ2/N)) = ((385-400)/√(352/100)) = -4.285 The p-value for the z-score is 0.000009, which...

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Your babysitter claims that she is underpaid given the current market. Her hourly wage is $12 per hour. You do some research and discover that the average wage in your area is $14 per hour with a standard deviation of 1.9. Calculate the Z score and use the table to find the standard normal probability. Based on your findings, should you give her a raise? Explain your reasoning as to why or why not.

The z-score is equal to: z = (12-14)/1.9 = -1.05 Given that the right-tailed p-value for this z-score is equal to 0.85, 85% of babysitters are paid more than my babysitter, which is why it is feasible to give her a rise.

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Cough-a-Lot children’s cough syrup is supposed to contain 6 ounces of medicine per bottle. However, since the filling machine is not always precise, there can be variations from bottle to bottle. The amounts in the bottles are normally distributed with σ = 0.3 ounces. A quality assurance inspector measures 10 bottles and finds the following (in ounces): 5.95 6.10 5.98 6.01 6.25 5.85 5.91 6.05 5.88 5.91. Are the results enough evidence to conclude that the bottles are not filled adequately at the labeled amount of 6 ounces per bottle? a. State the hypothesis you will test. b. Calculate the test statistic. c. Find the P-value. d. What is the conclusion?

a. H0: the mean volume of all the bottles is 6 ounces. Ha: the mean volume of all the bottles is not equal to 6 ounces. b. The z-score is equal to: z = ((x-μ)/√(σ2/N)) = 5.989-(6/√(0.09/10)) = -0.115 c. The p-value is equal to 0.907.d. The null hypothesis should...

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Drug A is the usual treatment for depression in graduate students. Pfizer has a new drug, Drug B, that it thinks may be more effective. You have been hired to design the test program. As part of your project briefing, you decide to explain the logic of statistical testing to the people who are going to be working for you. a. Write the research hypothesis and the null hypothesis. b. Then construct a table like the one below, displaying the outcomes that would constitute Type I and Type II errors. c. Write a paragraph explaining which error would be more severe, and why.

a. Ha: the effectiveness of drug B is greater than the effectiveness of drug A; H0: the effectiveness of drug B is equal to the effectiveness of drug A.b. Table 1 presents the outcomes of type I and type II errors. – – Reality Reality – – Drug B is...

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You want to investigate the workplace attitudes concerning new policies that were put into effect. You have funding and support to contact at most 100 people. Choose a design method and discuss the following: a. Describe the sample design method you will use and why. b. Specify the population and sample group. Will you include everyone who works for the company, certain departments, full or part-time employees, etc.? c. Discuss the bias, on the part of both the researcher and participants.

a. It is a good idea to choose stratified random sampling since it yields more accurate results, as compared to simple random sampling. Workers will be divided into groups by their position. Then, depending on the number of groups, a certain number of workers will be randomly chosen from each...

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An education expert is researching teaching methods and wishes to interview teachers from a particular school district. She randomly selects 10 schools from the district and interviews all of the teachers at the selected schools. Does this sampling plan result in a random sample? What type of sample is it? Explain.

This sampling plan does not result in a random sample because subgroups were randomly selected, and participants were not selected randomly. This is cluster sampling because the entire population was divided into internally heterogeneous groups (clusters), and several clusters were chosen for analysis using simple random sampling.

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The manager of a company wants to investigate job satisfaction among its employees. One morning after a meeting, she talks to all 25 employees who attended. Does this sampling plan result in a random sample? What type of sample is it? Explain.

This is not a random sample since employees who did not attend the meeting did not have a chance to be selected. Instead, this is convenience sampling since subjects were chosen only because the manager could easily access them.

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A phone company obtains an alphabetical list of names of homeowners in a city. They select every 25th person from the list until a sample of 100 is obtained. They then call these 100 people to advertise their services. Does this sampling plan result in a random sample? What type of sample is it? Explain.

This sampling plan does not result in a random sample since individuals do not have an equal chance to be chosen. In fact, individuals that are at the end of the list may be not even reached if there are more than 2,500 people living in the city. Since the...

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Describe how you could use regression analysis to help make a decision in your current job, a past job, or a life situation. Include a description of the decision, what would be the independent and dependent variables, and how data could ideally be collected to calculate the regression equation.

I could think of one way of using a simple linear regression model to help me make better health choices. Some time ago, I stumbled upon a piece of research that showed that regular exercise correlated with better sleep quality. While it is now pretty established that physical activity improves...

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Describe how you could use confidence intervals to help make a decision in your current job, a past job, or a life situation. Include a description of the decision, how the interval would impact the decision, and how data could ideally be collected to determine the interval.

Everyday use of the concept of confidence intervals that I can think of is buying clothes. It is common knowledge that sizing is often arbitrary and depends on the company. Sometimes, however, I think it is neither negligence nor malicious intent. People come in many shapes and sizes, and it...

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Describe how you could use hypothesis testing to help make a decision in your current job, a past job, or a life situation. Include a description of the decision, what would be the null and alternative hypotheses, and how data could ideally be collected to test the hypotheses.

When I waited tables a few years ago, I was often curious about the average number of restaurant visitors depending on the day of the week. The information was of value to me because I wanted to know what to expect from a shift, and some of them were really...

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After several grueling months of data collection and statistical analysis, you finally were able to test the following hypothesis: Null hypothesis: There is no relationship between yearly changes in Gross Domestic Product (GDP) and yearly changes in the national deficit. Alternative hypothesis: There is a relationship between yearly changes in Gross Domestic Product (GDP) and yearly changes in the national deficit. Your results told you to reject the null hypothesis (Χ2(4) = 2.35, p = 0.012). However, what did the p-value tell you about the results of the hypothesis test?

Scholars emphasize the significance of the p-value in scientific research and statistics. P-value is the probability of receiving the result that is at least as extreme as the one mentioned in the sample data with the assumption that the null hypothesis is true. When the p-value is less than the...

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a. Show how you can use numbers, tables and graphs to describe a single set of values. b. Show how you can use numbers, tables and graphs to describe an association between two sets of values.

Numbers, tables, and graphs are very useful when describing a single set of values or showing an association between two sets of values. A single set of values are used in everyday life. For instance, the teaching staff is fond of using single sets of values when evaluating the learners’...

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