# Stats TEST 1 PREP

 .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } what are the 2 types of data? CategoricalQuantitative What is Categorical data? Data made up of categories (not numbers) with "usual meaning How do you compute Relative Frequency? Frequency divided by total What is Statistics? Science of using data to analyze questions of interest and draw conclusions. What is the experimental unit? It is the object which you are studying What is the experimental unit if you're studying the GPA of students? Each individual student What is a population in statistics?..give example. A collection of all experimental units of interestEx: an entire student body What is a statistical census? This is a method for finding attributes of all members of a statistical population of interest What is a statistical sample? A subset of an entire population What are the 3 major branches of statistics? DescriptiveProbabilityInferential What is Descriptive Statistics? Utilizes techniques to describe attributes of data sets What is Probability Statistics? This tells us what sorts of inferences we can make about a population based on the sample What is Inferential Statistics? Drawing conclusions from a sample that might be applicable to the whole population What is a statistical variable? A characteristic of the experimental unit of interest What are the 2 types of variables? Categorical and Quantitative What is a quantitative variable?..and give an example. Variable that has natural ordering and are numericEx: Money What is a discrete quantitative variable and give an example. This is a quantitative variable that can only take discrete numerical values?Ex: Integers What is a continuous quantitative variable..example? This is a variable that can take on any numerical valueEx: All Real #s If a variable is bounded, can it not qualify as continuous..exxample? No. A variable can be bounded and still be continuous.Ex: Non-negative #s Found by adding up all of our data and dividing by number of data points Mean If a statistical attribute (ex: mean) changes a lot when we change large values and changes little when we change little values then it is: Not Resistant Is mean a resistant statistical attribute? No What is median? The middle value when a set of sample #s are ordered numerically If a statistical attribute (ex: median) doesn't change at all when a new value is introduced to it then it is... Resistant Is median resistant? Yes If you have an even number of values, how do you find their median when ordered numerically? the median is the mean of the middle 2 values in the order. If the mean is roughly equal to the median, what shape would you expect your data set to be? Symmetric What cane you say about the shape of the data if the mean is greater or less than the median? If mean is greater then positive skewed; if less than the median then it is negatively skewed What is the mode? The value that appears most often This is specifically the equation for... Sample Standard deviation This is the formula for... And what does Mu stand for in this? Population Standard DeviationMu is population mean This is the formula for Sample Variance (Standard Deviation squared) What are Q1, Q2, and Q3 for IQR? Q1=Median of 1st half of data setQ2= median of full setQ3= Median of 2nd half of set Are the quartiles in IQR and the IQR itself resistant? yes If you have an odd number of data, what do you do with the middle value when calculating quartiles? The middle value is included in both Q1 and Q3 calculations. Name the resistant measures of spread and center meanIQR Name the non-resistant measures of spread and center meanrangestandard dev How do you designate the range in which a value is considered and outlier? If it is less than Q1-1.5*IQRorIf it is greater than Q3+1.5*IQR When can you drop and observation from a data set? When you are certain of it being a mistakeWhen you know the observation came from the wrong population What does the Empirical rule say about data? 68% of data falls within the first standard deviation, 95% falls within the second standard deviation, and 99.7% of the data falls within 3 standard deviations What are the characteristics of bell-shaped data? symmetricunimodalmean and median are relatively close to each other How do you calculate statistical density? Density = Relative Frequency divided by groupwidth What are some topics you should include when summarizing a set of data shapespreadrangecenter What is the easiest way to find the skewness of a set of data? Find the mean and compare it to the medianIf the mean is greater than the median then you have positive skewIf mean is less than median then negative skew .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } Authorballinbc14 ID61709 Card SetStats TEST 1 PREP DescriptionBasic preparation for Stats 1100Q Updated2011-02-18T07:56:43Z Show Answers