Section 1.1 - Introduction to the Practice of Statistics 1. Explain the difference between a population and a sample. A population is the entire group to be studied and a sample is a portion of the population. 2. Explain the difference between a parameter and a statistic. A statistic is a numerical summary of a sample and a parameter is a numerical summary of a population. 3. What is Descriptive Statistics and how is it used? Descriptive statistics describes the results of a sample without
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Standard deviation is the square root of the variance (Gravetter & Wallnau‚ 2013). It uses the mean of the distribution as a reference point and measures variability by considering the distance of each score from the mean. It is important to know the standard deviation for a given sample because it gives a measure of the standard‚ or average‚ range from the mean‚ and specifies if the scores are grouped closely around the mean or are widely scattered (Gravetter & Wallnau‚ 2013). The standard deviation
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Null Hypothesis: No differences between population means. µ1=µ2=µ3 Alternative Hypothesis: At least one pop mean is different from at least one other pop mean. (Can’t use symbols) 3) Numerator of the F statistic measures between groups variance (MSbetween) 4) Denominator of the F statistic measures within groups variance (MSwithin) 6) A priori test: planned ahead of time‚ before you collect data decide on test‚ based on reasoning Post hoc: choose after you look at data; based on data‚ choose
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Statistics Direct/Interview method * One of the modes of administration of survey method used for collecting primary data * This is a method of person-to-person exchange between the interviewer and the interviewee. * This method provides consistent and more precise information since clarification may be given by the interviewee. Advantages of interviews * they are useful to obtain detailed information about personal feelings‚ perceptions and opinions * they allow more detailed questions
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Question 1: State the null hypothesis and alternative hypothesis ONLY i) One of the major Malaysia tire makers wishes to review its warranty for their rainmaker tire. The warranty is for 40‚000 kilometers. The tire company believes that the tire actually lasts more than 40‚000 kilometers. A sample 49 tires revealed that the mean number of kilometers is 45‚000 kilometers with a standard deviation of 15‚000 kilometers. What is the null hypothesis and alternative hypothesis? ii) It is claimed
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Drunk Driving Statistics In a study conducted by MADD (Mother’s Against Drunk Driving)‚ during the years 1999 to 2008 there were a total of 2‚050‚132 impaired driving accidents. The total cost of these accidents was an estimated $205.3 billion. That is approximately $6‚221 per Canadian. Broken down annually‚ the estimated cost to Canadians is $20.53 billion‚ or approximately $622 per person per year. Besides the cost‚ fatalities are a massive issue when it comes to driving under the influences
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standard deviation were used to describe the length of labor. These were appropriate since mean and standard deviation can be calculated on an interval level of measurement. 3. Range could also be used to describe the length of labor since this statistic can be used on interval data with no natural zero point. 4. The distribution of scores was similar for the experimental and control groups for length of labor. The experimental group had a mean of 14.63 hours and the control group had a mean of
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I read Barron’s How to Prepare for the AP Statistics Exam. A very educational book helped a lot on the AP test. It clarified ideas that I was uncertain on. It helped me to understand when to use each test and the assumptions needed for each test. Type I and Type II errors were explained in such a way that they became crystal clear to me instead of muddy. Computer and Minitab outputs were thoroughly explained‚ and I became comfortable with them after reading this book. The Barron’s guide also
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Chapter 12 Simple Linear Regression Case Problem 1: Measuring Stock Market Risk a. Selected descriptive statistics follow: Variable N Mean StDev Minimum Median Maximum Microsoft 36 0.00503 0.04537 -0.08201 0.00400 0.08883 Exxon Mobil 36 0.01664 0.05534 -0.11646 0.01279 0.23217 Caterpillar 36 0.03010 0.06860 -0.10060 0.04080 0.21850 Johnson & Johnson 36 0.00530 0.03487 -0.05917 -0.00148 0.10334
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The U.S. Department of Justice Office of Justice Programs reviews arrest records from law enforcement agencies throughout the United States documenting statistics in relation to juveniles‚ location‚ and crime types. The statistical information developed and presented is used to help law enforcement agencies and individuals with interests in juvenile justice to develop programs to lower the types of crimes and help juveniles to refrain from committing crimes. The Juvenile Justice Bulletin of 2008
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