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Review for Exam 1 Ch 1-5 Ch 1-3 Descriptive Statistics Descriptive Statistics Ways to collect, describe, and present data Collect data Population vs. Sample Statistical Sampling Technique a) Simple random b) Stratified c) Systematic d) Cluster Data Types Primary vs. Secondary Qualitative vs. Quantitative Measure levels: a) Nominal (group, compare, mode) b) Ordinal (everything you can do for level a, + sort, median) c) Interval (everything you can do for level b, + subtraction, zero ≠ nothing) d) Ratio (everything you can do for level c, + division, zero = nothing) BUS304 – Review Chapter 1-5 1 Ch 1-3 Graphical Presentation Qualitative Categorical (Nominal, Ordinal) start Bar Chart or Pie Chart or Relative Frequency Frequency Limited Categories Data Type Data class Quantitative (Discrete/continuous, Interval/Ratio) Bar Chart Line Chart Relative Frequency Frequency Continuous Range Two sets of continuous variables – relationship BUS304 – Review Chapter 1-5 Histogram Scatter Chart 2 Procedures to create a histogram Create a frequency table Identify the range of data: Range = Rounded maximum - Rounded minimum Identify the width of each category: Width = Range / Number of bars Write down the lower and upper bound for each bar Lower limit Upper limit Frequency Rounded min =lower limit + width Count numbers =upper limit of above category =lower limit + width Count numbers … … Count numbers =upper limit of above category =lower limit + width = rounded max Count numbers Remember to verify the total frequency = sample size BUS304 – Review Chapter 1-5 3 Ch 1-3 Numerical Characterization Measure of central tendency: Mean sum up all the data values = sample or population size Median the i th data value, i= sample or population size+1 2 Mode the data value repeats the most frequently Measure of Variation Range =max-min Variance average squared deviation from the mean (4 steps) Standard Deviation square root of variance Other Location Related Measures (find location first) Percentiles/Quartiles (Calculate location first, then go find the value) Interquartile range BUS304 – Review Chapter 1-5 4 Chapter 4 Probability Theory Key concepts Experiments and events • Identify elementary events and sample space Relationship among events: • Complement Events, P(E1 ) =1- P(E2 ) • Mutually Exclusive Events, P(E1 and E2 ) = 0 • Conditional Probabilities, P(E1 | E2 ) = P(E1 and E2 ) / P(E2 ) • Independent Events. P(E1 and E2 ) = P(E1 )*P(E2 ) Mean (expected value) and SD of a random variable • Mean – weighted average of all possible values (weights are the probs). • Variance – weighted average of the squared deviation from the expected value. BUS304 – Review Chapter 1-5 5 Chapter 5 Normal distribution Continuous random variable Given the mean and standard deviation (variance sometimes, pay attention to the notation), how to compute the probability. 5/24/2017 BUS304 – Midterm Review 6