STA2023 Quiz 1 – 10 Answers|ALL ANSWERS CORRECT|VERY HELPFUL

STA2023 Quiz 1 Answers Statistics (definition) the art and science of learning from data Design plan how to obtain the data Description summarize the data with graphs and numerical summaries Inference use data from a random and representative sample to draw conclusions about the population of interest What are the two types of Statistical Inference? Confidence and Significance tests Subjects persons, animals, or objects in a study/experiment Variables the characteristics that we measure on each subject Population all subjects of interest Sample subjects for whom we have data Random Sampling each member of the population has the same chance of being included in the sample Parameters numerical(proportion) summary of the population Statistics numerical summary of the sample Categorical Variables place observations into groups summarized by percentage (yes or no, eye color) Quantitative Variables take on numerical values; key features are center (average) and spread (variability) Types of Quantitative Variables Discrete and Continuous Discrete take only a finite list of possible outcomes; a count Continuous has an infinite list of possible values that form an interval; limit to measurability Mound or Bell-shape normal Uniform or Rectangular different values with the same proportions in a population (height) Bimodal distinct valley; two centers Skewed left direction of the long tail (left) Skewed right direction of the long tail (right) Statistics The study of how to collect, organize, analyze, and interpret numerical and categorical information. Scientific Method A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions (choose, perform, develop, design, gather, analyze, formulate) descriptive statistics Numeric values(graphs) calculated from a dataset with the purpose of characterizing the behavior of the variables inferential statistics involves methods of using information from a sample to draw conclusions regarding the population Population set of all the individuals of interest in a particular study Finite population A population in which each individual member can be given a number infinte population collection of objects or individuals that are no boundaries or we can not measure about the total number of individuals in the occupied territories sample subset of the population. individuals selected from a population, usually intended to represent the population in a research study Parameter value that describes a population Statistic Value that describes a sample Variable A characteristic about each individual element of a population or sample Data (singular) value of the variable associated with one element of a population or sample. This value may be a number, or a symbol Data (plural) the set of values collected for the variable from each of the elements belonging to the sample Experiment a planned activity whose results yeild a set of data Sampling error naturally occuring discrepency between a sample statistic and the cooresponding population parameter Individual the objects described by a set of data: person (animal), place, and thing. In a medicinal trial, the people in the study referred to as called subjects Valid Measure one that is relevant or appropriate asa representation of that property. Reliable Measure measurement such that the random error is small Census In Population data, the variable is measured for EVERY individual of interest Sample Survey in sample data, the variable is measured from ONLY SOME of the individuals of interest Quantitative (Numerical) variable variable that quantifies an element of the population. has a numerical measurment for which operations such as addition or averaging make sense. Ex: Ag, GPA, Tuition, Fees Qualitative (attribute) variable A variable that categorizes or describes an element of a population. has a nominal measurement that descibes an individual by placing them in a category or group. Ex: Phone number, college year, addresses. Discrete variable characterized by gaps or interruptions in the values we assume. gaps implies absence between those values. ALl values are whole numbers Ex: number of cars in garge, count of males in a group Continuous variable does not possess the gaps or interruptions characteristic of a discrete variable. decis