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Statistics and Probability Question

 3.A researcher wonders if students will spend more time studying for a quiz if they are told that a high mark on that quiz will excuse them from writing a term paper. Two groups of college students were randomly selected from a large lecture course in art history. The students in Group 1 were simply told that they would have their first art-history quiz two days later. In Group 2, they were told the same thing, except that the promise of “no term paper” for high quiz performance was added. Just before taking the quiz, all students in both groups reported (in hours) the time they had spent preparing. In Group 1, the times were 6, 4, 7, 3, 2, 5, 7, 4, 7, 6. In Group 2 the times were 12, 9, 13, 10, 8, 7, 9, 6, 9, 6.
4. What is the IV?
5. What is the DV?
6. Calculate the means for each group
7. Calculate the standard deviations for each group
8. Calculate the standard errors of the means for each group
9. Calculate the SED for both groups combined
10. Calculate the independent t ratio 11. Is this a one-tail or two-tail hypothesis?
12. Do you reject or accept the null hypothesis?
13. Is the effect size small, medium, strong, or insignificant?
14. Are the two groups homoscedastic? 15. Based on your answer to #
15, what does that mean with regard to the two samples in problem # 4?
16. What test of significance is used to determine equality of variances between the two groups?
17. Write a sentence interpreting the outcome of the analysis.
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Probability and Statistics

1. In the 2012 Presidential election, Florida was one of the swing states in which no single candidate or party had overwhelming support. In a poll completed November 1, just one week before the election, the Tampa Bay Times found 51% in favor of Romney, 45% in favor of Obama and 4% undecided. On November 3rd, the opening line in the article of the Tampa Bay Times that reported the results of this poll sais “Florida continues to look good for Mitt Romney.” The poll was based on a sample of 800 likely voters. On election day, Romney received 49.1% of the votes in Florida and lost the state. What happened?
a) For each of the boldface numbers, indicate whether it is a parameter or a statistic. Explain your answer.
b) Suppose 49.1% of all voters supported Mitt Romney at the time of the poll. What are the mean and the standard deviation of p^ (pHat), the proportion of voters in a SRS of 800 voters who would support Romney?
c) Suppose 49.1% of all voters supported Mitt Romney at the time of the poll. What is the probability that at least 51% of the voters in an SRS of 800 voters would support Romney?

2. Greeks bucked a global trend in which people in most countries except their lives in five years to be better than their current lives. Even among those countries with much lower current life ratings, greater than optimism was found because people cannot fathom their lives getting worse. But in Greece, only 25% expect their lives to be better in 5 years than currently. In an SRS of 500 greek citizens, what is the probability that less than 30% of the sample expect their lives in 5 years to be better than their current lives?

3. Approximately 20% of cars in the US are white. You take an SRS of 300 cars parked in student lots on your campus and find 42 are white. For this problem, you can assume that you have obtained an SRS of student cars on campus.
a) what is the proportion, p^, of white cars in your sample?
b) If 20% of student cars on campus are white, what proportion of samples wpuld give a value of p^ as small as the value computed in (a)?
c) There are two explanations for your sample result. The first is that you obtained a sample with an unusually low percentage of white cars. What is an alternative explanation?

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In an SRS of 500 Greek citizens, what is the probability that less than 30% of the sample expect their lives in 5 years to be better than their current lives?

Greeks bucked a global trend in which people in most countries except their lives in five years to be better than their current lives. Even among those countries with much lower current life ratings, greater than optimism was found because people cannot fathom their lives getting worse. But in Greece, only 25% expect their lives to be better in 5 years than currently. In an SRS of 500 Greek citizens, what is the probability that less than 30% of the sample expect their lives in 5 years to be better than their current lives?

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Year 2016 is the election year for American president. One researcher wants to conduct a telephone survey to study the proportion of Americans who do not know that GOP stands for Grand Old Party.

Year 2016 is the election year for American president. One researcher wants to conduct a telephone survey to study the proportion of Americans who do not know that GOP stands for Grand Old Party.

a)What is the minimum number of Americans the researcher should have in a telephone survey to estimate the proportion of Americans who do not know that GOP stands for Grand Old Party within 3% margin of error at 95% confidence level?

b)Suppose one past study has shown that 55% of Americans who do not know that GOP stands for Grand Old Party. What is the minimum number of Americans the researcher should have in a telephone survey to estimate the proportion of Americans who do not know that GOP stands for Grand Old Party within 3% margin of error at 95% confidence level?

c)According to a telephone survey from a random sample of 1, 900 Americans, 1, 049 Americans do not know that GOP stands for Grand Old Party.

c )Construct a 95% confidence interval for the proportion of Americans who do not know that GOP stands for Grand Old Party.

d)Interpret the interval constructed in part (c).

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Presidential Physical Fitness exam

The American Heart Association conducted a study showing that only 20% of adults can meet the requirements to pass the Presidential Physical Fitness exam. If we do a study with 10 adults, what is the probability that exactly 3 will fail the exam?

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Quantitative Study of African Americans with type 2 Diabetes mellitus

You are interested to study age (18 – 85 years old), gender (male/female), self –efficacy (low, moderate, high), neighborhood safe for physical activity (yes/no), and physical activity (minutes per week) in a .

What is your indepedent variable?
What is your dependent variable?

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Statistics

You desire to do a study of ax murderers in American prisons. A preliminary study reveals that the mean IQ of a random sample of 156 ax murderers is 80, with a standard deviation of 24. Perform a 95% confidence interval on the mean IQ of ax murderers, and provide the interval. What exactly does this confidence interval tell me? (Be scientific, not sociological.)

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Empirical Methods in Communication

Empirical Methods in Communication

Briefly answer five essay questions that require you to dissect an experiment by Palomares and Lee, that was published in a 2010 issues of the Journal of Language and Social Psychology. Your answers must be typed and double spaced. Provide a 1½ inch margin on all sides of the page for written comments. Your paper must absolutely not be longer than 1000 words; that is about 200 words per question. All word processors have a word count feature. Please provide the word count of your essay (excluding your name and other identifying information).
Questions
1. Palomares and Lee used a 2x2x2 between-subjects factorial design. (This kind of design
is referred to as “between-subjects” because each research participant was assigned to
only one experimental condition.) Explain why this design was necessitated by the
research hypothesis.
2. Experimental control is a critical feature of any experiment. If we wish to know the effects
of independent variables on dependent variables we must “hold constant” other variables
that would make causal inference challenging. What efforts were taken in this experiment
to achieve a high level of experimental control?
3. What efforts were made to determine if the manipulations of the independent variables
were valid?
4. Did this experiment measure any potential mediating variables? If so, what were these
variables? If no, why not?
5. The generalizeability of every experiment has limitations, and this study is no exception.
Briefly describe how our ability to generalize from the findings obtained are limited.
Evaluation
Your answers to these five questions will be equally weighted. Evaluation is based on the
thoughtfulness of your response and the quality of your writing..

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Statistics

 
1. Plot distributions (histograms) of each of these four variables, using either:
a. Engineering paper, manually preparing these plots

b. Excel which can prepare these distributions for you

2. Ensure you identify the mean value on each plot and also determine the following statistics to demonstrate the variation of queuing performance:

a. For each variable, calculate the probability that the data will exceed 125, 150, 175 and 200% of the mean

b. Determine each increment until the statistic reaches near zero

c. Again you can do these calculations manually or by Excel

Note: Make graphs out of the excel sheet provided, and a graph of the interarrival times, the t que, the t ser, and the t sys.

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Data Warehousing for Business Intelligence – Data Mining

Your aim is to identify which attribute or combination of attributes and which algorithm has the highest accuracy in identifying adults who would be given a ‘good’ credit rating. Once you have completed this, write a report to describe in detail the analyses you have performed.

Your report should include:
• A data set description in terms of the attributes present in the data, the number of instances, missing values, and other relevant characteristics.
• A detailed description of the pre-processing of the data.
• Evidence that you have investigated the data using multiple analysis methods.
• An explanation of the selected algorithm.
• A discussion of any pre or post processing done to improve the accuracy of your analysis.
• A business recommendation based upon your analysis.
The report should be no more than 2500 words long and should include such graphics as are appropriate to illustrate your answers.

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