deviation = σ = sqrt [ Σ ( Xi - μ )2 / N ] * Population variance = σ2 = Σ ( Xi - μ )2 / N * Variance of population proportion = σP2 = PQ / n * Standardized score = Z = (X - μ) / σ * Population correlation coefficient = ρ = [ 1 / N ] * Σ { [ (Xi - μX) / σx ] * [ (Yi - μY) / σy ] } Statistics Unless otherwise noted‚ these formulas assume simple random sampling. * Sample mean = x = ( Σ xi ) / n * Sample standard deviation = s = sqrt [ Σ ( xi - x )2 / ( n - 1 ) ] * Sample variance
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Lab 2 – Water Quality and Contamination Experiment 1: Effects of Groundwater Contamination Table 1: Water Observations (Smell‚ Color‚ Etc.) Beaker Observations 1 This beaker has water only‚ clear with no smell 2 I mixed oil in the water‚ the oil then started to settle at the top of the water. (oil is not a soluble) 3 Beaker contained vinegar and water‚ the water got a little cloudy and the vinegar smell is very strong. 4 The water and laundry detergent mix had a soapy look to it‚ water also
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basic operational rules which help to simplify the use of the sigma notation. 1. For any integer N Operational Rules for Summation N i i N i i N i i i y x y x 1 1 1 2. If c is a constant‚ that is‚ does not depend on the index of summation i‚ then Continue... Nc c and x c cx N i N i i N i i 1 1 1 The graphical representation of data gives us the idea on the shape of the distribution (population).
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Comparison of Crime Statistics Crime statistics endeavour to provide statistical measures of crime in societies. They provide a point of analysis and comparison‚ allow countries to form long-term patterns and trends and can help to develop and reform criminal justice policies as well as being more meaningful than raw numbers. Using the countries of Bahrain and the United States as a comparison point for the following issues which surround crime statistics such as biases‚ agendas and general influences
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18. Based on a simple random sample of one hundred an analyst estimates the average hourly wage earned by workers in a city to be $30 and computes the margin of error to be $5. Can we conclude from this that most workers there earn between $25 and $35 per hour? Is the right interpretation for the margin of error? 23. Polls showed the two main candidates in the 2004 presidential election were nearly tied on the day before the election. To predict the winner a newspaper would like to have a poll
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Module 1 Suppose you hear an "old-timer" say‚ "Why‚ in my day‚ kids were much more respectful and didn’t cause as much trouble as they do nowadays!" Formulate a hypothesis related to this statement that you could test. How would you test it? The old-timer are the older person in their 70s or 80s at this time. I would compare the age when this old timer is raising his own children . what actually age he may be‚ let say‚ 25 years old if he was born in 1940 by the year 1965 to determine respectfulness
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□ EXERCISE 16 Questions to be Graded 1. The researchers analyzed the data they collected as though it were at what level of measurement? d. Experimental 2. What was the mean posttest empowerment score for the control group? The mean posttest empowerment score for the control group was 97.12 3. Compare the mean baseline and posttest depression scores of the experimental group. Was this an expected finding? Provide a rationale for your answer. The mean baseline depression score of
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copy and the copy is used for educational‚ not-for-profit purposes. PREDICTING VIOLENT CRIME USING URBAN AND SUBURBAN DENSITIES Brian Christens1 & Paul W. Speer Vanderbilt University ABSTRACT: Violent crime is often studied with individual level variables‚ using population characteristics as predictors. This study attempts to predict an additional amount of the variability in violent crime using an environmental variable—population density—in a single U.S. city. Data aggregated to the census
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Research and Statistics in Psychology Tracy Charles PSY/315 October 14‚ 2012 Jennifer Slothower Research and Statistics in Psychology Psychologist need to adhere to scientific research methods when doing a study “the scientific method requires systematic observation and a willingness to modify understanding based on these observations” (Cloninger et al.‚ 2008). This method involves careful observation and collection of data to rule out theories that are not valid. “Scientific
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Week Two Assignment BUS308: Statistics for Managers Tiffany Aldridge January 9‚ 2012 Week Two Assignment Chapter 4: 4.4‚ 4.20 4.4 Suppose that a couple will have three children. Letting B denote a boy and G denote a girl: a. Draw a tree diagram depicting the sample space outcomes for this experiment b. List the sample space outcomes that correspond to each of the following events: 1) All three children will have the same gender. BBB‚ GGG 2) Exactly two of the three
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