# Test 1 Elementary Stat UTA

Classified in Mathematics

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MAKE SURE TO READ THE QUESTIONS CAREFULLY!!!
Chapter 3

Missing variable: x=given Median*2-((1 of 2) median numbers if even): ascending order:::unreadable score- (U*N of unreadable)-(U*N of readable):::degrees of freedom=1 # of freedom is lost:::CHEBS- K=Deviaton::Calculate time % within K Dev of mean- (1-1/k^2)100=%:::Find Values- find x K devs from mean- (mean-K*given standard dev)=XLow...(mean+k*given standard dev)= XHigh::Find % within times Xlow-Xhigh: K=(XHigh - Mean)/Given Standard dev....Then do chebs- (1-1/k^2)100=%:::Z SCORE Simplified: (Mean-Given Mean)/Given Standard Dev=ZScore:::Find min score accepted: (Min devs)*(Given Devs)+(Mean)=Min Score:::Weighted Mean: Chart Xi / Wi /XiWi..Use Empirical Rule if dist. Is bell shaped. Sum of Dev's = 0:  range does not use all observations::The more Dispersion the Higher the Standard of Dev

Chapt 2
Stat= Science of organizing data to draw conclusions::Descriptive Stat=describe date through numerical summaries or graphs, "for those surveyed"::Variables=characteristics if indiv in pop::Discrete=you can count 1,2,3::Cont=you measure 1.2,1.34,1.675 etc::Nominal-Name, Ordinal- Nom+rank/order, Interval- 0 has no meaning equal space between #'s, Ratio- 0 has meaning can be any #'s (factory quest)::Response-what is being studied, Explanatory-variable that affects response, Factor- variable whose effect on the response variable is to be assessed by the experimenter Confounding- not separating variables, Lurking- explanatory variable not considered::Studies only show assoc.::Cross-Sectional-Group of people in short amount of time, Case-Control-Looking to past for answers, Cohort-Group of people over a long time. Frame- List of indiv being studied, not always accurate because pop is always changing, Simple Random Sampling-Pick names out of a hat or chart, not always preferred expensive,Stratified-Separating pop into different groups then obtaining a simple random of indiv from each group, Systematic Random- selecting every nth indiv, Does not require frame; K= Pop/Sample, p, p+k, ...P+(N-1)*k :::Cluster- Randomly selecting  group then obtaining sample from all, Bias- sample does not represent pop, NonSampling Bias- under coverage(smaller in sample) or favors one part of pop, may result from non response or improperly worded questions, Experiment-study conducted to determine the effect of 1 or more explanatory has on a response, Treatment-combination of the values of factor, Experimental Unit-person being studied, Matched Pairs- before and after, husband and wife:: Relative Freqs-add up to 1:: Charts- Stem and leaf plots not good for large data but show original data, Histograms- Organize data of all sizes. Difference between values between quarters- (High - Low) / High, difference values of highest and lowest (high-low) / Low:: Class Width- (Max entry - Low entry)/Number of entries:: Quantitive variables are required for time plots:: > = greater than, <= Less than