statistics and other decision sciences

... Categorical and Numerical Data Categorical Data  Type of purchase made and Brand of bike are examples Trang 82.2 Categorical and Numerical Data Numerical Data  Size of bike (cm) and Amount ... with rows and columns attributes or variables form the columns Trang 42.1 Data TablesDisorganized Data Trang 52.1 Data TablesSame Data in a Data Table Trang 62.1 Data Tables formatting and units ... examples Trang 92.2 Categorical and Numerical Data subtracted (no absolute zero) subtracted, multiplied or divided (makes ratio comparisons possible) Trang 102.2 Categorical and Numerical Data Likert

Ngày tải lên: 10/01/2018, 15:59

... variation in song sizes and the shape of its distribution, we can say that most collections of 500 songs will fit! Trang 39Best Practiceshistograms and summaries such as the mean and standard deviation ... answer this question we must understand the typical length of a song and the variation of song sizes around the typical length  We can do this using summary statistics Copyright © 2011 Pearson ... categories) Trang 234.2 Histograms and the Distribution of Numerical Data Histogram of Song Sizes Copyright © 2011 Pearson Education, Inc. 23 of 42 Trang 244.2 Histograms and the Distribution of Numerical

Ngày tải lên: 10/01/2018, 16:00

... Counts and Percentages) Trang 85.1 Contingency TablesConditional Distribution • Reveals the percentage of purchases among visitors from RecipeSource to be much less than for MSN and Yahoo • Host and ... contingent on the value of another (for every combination of both variables) Trang 55.1 Contingency TablesContingency Table for Web Shopping Trang 65.1 Contingency TablesMarginal and Conditional Distributions ... stolen than other popular models The data suggest that higher premiums for theft insurance should be charged for models that are more likely to be stolen. Trang 205.2 Lurking Variables and Simpson’s

Ngày tải lên: 10/01/2018, 16:00

... Association in Scatterplots Visual Test for Association  Compare the original scatterplot to others that randomly match the coordinates  If you can pick the original out as having a pattern, then ... measurement and is therefore difficult to interpret of 30 Copyright © 2011 Pearson Education, Inc 6.3 Measuring Association Correlation (r) cov( x, y ) corr( x, y ) = S x Sy    Standardized ... association between sales at the retail outlets and distance to nearest competitor? For 55 stores in the chain, data are gathered for total sales in the prior year and distance in miles from the nearest

Ngày tải lên: 10/01/2018, 16:00

... 33 Trang 49.1 Random VariablesDefinition of a Random Variable  Describes the uncertain outcomes of a random process  Denoted by X  Defined by listing all possible outcomes and their associated ... 2011 Pearson Education, Inc. 9 of 33 Trang 109.1 Random VariablesRandom Variables as Models  A random variable is a statistical model  A random variable represents a simplified or idealized ... probability distribution for a random variable Trang 119.2 Properties of Random VariablesParameters  Characteristics of a random variable, such as its mean or standard deviation  Denoted typically

Ngày tải lên: 10/01/2018, 16:00

... to understand portfolios  Since stocks tend to rise and fall together, random variables for these events must capture dependence Trang 410.1 Portfolios and Random VariablesTwo Random Variables ... Trang 3310.5 IID Random VariablesTrang 3410.5 IID Random VariablesAddition Rule for iid Random Variables If n random variables (X 1 , X 2 , …, X n) are iid with mean µ x and standard deviation ... Dependence Between Random Trang 2410.4 Dependence Between Random Variables Positive Dependence Between X and Y Trang 2510.4 Dependence Between Random Variables Covariance and Sums The variance

Ngày tải lên: 10/01/2018, 16:00

...  Need a discrete random variable to model counts and provide a method for finding Trang 411.1 Random Variables for CountsBernoulli Random Variable Bernoulli trials are random events with three ... probability of success (p) Trang 511.1 Random Variables for CountsBernoulli Random Variable - Definition A random variable B with two possible values, 1 = success and 0 = failure, as determined in ... the mean number of defects and the standard deviation? Trang 254M Example 11.2: DEFECTS IN SEMICONDUCTORS Method The random variable is the number of defects on a randomly selected wafer The

Ngày tải lên: 10/01/2018, 16:00

... Normal Random Variable Definition A continuous random variable whose probability distribution defines a standard bell-shaped curve of 45 Copyright © 2011 Pearson Education, Inc 12.1 Normal Random ... independent random variables of comparable variance tends to a normal distribution as the number of summed random variables increases of 45 Copyright © 2011 Pearson Education, Inc 12.1 Normal Random ... (Continued)  Estimate normal probabilities using a sketch and the Empirical Rule  Be careful not to confuse the notation for the standard deviation and variance 44 of 45 Copyright © 2011 Pearson Education,

Ngày tải lên: 10/01/2018, 16:00

... members of the population at random.  Larger populations do not require larger samples. Trang 613.1 Two Surprising Properties of SamplingRandomization  A randomly selected sample is representative ... SamplingSimple Random Sample (SRS)  A sample of n items chosen by a method that has an equal chance of picking any sample of size n from the population.  Is the standard to which all other sampling ... simple random sample to select items from each strata Trang 2413.3 ALTERNATIVE SAMPLING METHODS Cluster Samples  Divide a geographic region into clusters  Randomly select clusters  Randomly

Ngày tải lên: 10/01/2018, 16:00

... Concepts of Statistical Tests Type I and II Errors  indicates a correct decision of 40 Copyright © 2011 Pearson Education, Inc 16.1 Concepts of Statistical Tests Other Tests  Visual inspection ... one-sided test of 40 Copyright © 2011 Pearson Education, Inc 16.1 Concepts of Statistical Tests One- and Two-Sided Tests  One-sided test: the null hypothesis allows any value of a parameter larger ... parameter of 40 Copyright © 2011 Pearson Education, Inc 16.1 Concepts of Statistical Tests Type I and II Errors  Reject H0 incorrectly (buying software that will not be cost effective)  Retain

Ngày tải lên: 10/01/2018, 16:00

... that moves the sampling distribution of closer to ½ and away pˆ from the troublesome boundaries at and  Add four artificial cases (2 successes and failures) to create an adjusted proportion ~ ... with median θ, then we know The probability that a random draw from the population is less than or equal to θ is ½, The observations in the random sample are independent 10 of 35 Copyright © 2011 ... confidence interval for θ is to sort the observed data in ascending order (known as order statistics)  Order statistics are denoted as X(1) < X(2) < … < X(n) of 35 Copyright © 2011 Pearson Education,

Ngày tải lên: 10/01/2018, 16:00

... a promotional offer, an overnight service pulled records for a random sample of 50 offices that received the promotion and a random sample of 75 that did not Copyright © 2011 Pearson Education, ... the effects of two or more factors when comparing treatments.  Randomization eliminates confounding.  If it is not possible to randomize, then sample independently from two populations. Copyright ... U Penn selected 63 subjects from the local population of obese adults They randomly assigned 33 to the Atkins diet and 30 to the conventional diet Do the results show that the Atkins diet is

Ngày tải lên: 10/01/2018, 16:00

... relationship between the price and weight of diamonds?  Use regression analysis to find an equation that summarizes the linear association between price and weight  The intercept and slope of the line ... Trang 2519.3 Properties of ResidualsStandard Deviation of Residuals (se)  Measures how much the residuals vary around the fitted line  Also known as standard error of the regression or the ... ResidualsStandard Deviation of Residuals Since the residuals are approximately normal, the Trang 2719.4 Explaining VariationR-squared (r2)  Is the square of the correlation between x and y 

Ngày tải lên: 10/01/2018, 16:00

... Standard deviation of the residuals As it increases, the standard error increases  Sample size As it increases, the standard error decreases  Standard deviation of x As it increases, the standard ... histogram and quantile plot of the residuals Trang 2021.3 Inference in RegressionParameters and Estimates for SRM Trang 21s n s s n s b Trang 2221.3 Inference in RegressionEstimated Standard Error ... the catch will be between 908,440 and 1,438,110 pounds Trang 48Best Practices Verify that your model makes sense, both visually and substantively  Consider other possible explanatory variables

Ngày tải lên: 10/01/2018, 16:01

... average and standard deviation in price Trang 522.1 Problem 1: Changing VariationSRM Results: Home Price Example Trang 622.1 Problem 1: Changing VariationFixed Costs, Marginal Costs, and Variable ... the revised model has a smaller r 2,  It provides more reliable and narrower confidence intervals for fixed and variable costs; and  It provides more sensible prediction intervals Trang 2522.1 ... your model if it does not match the data  Report the presence of and how you handle any outliers Trang 47 Do not rely on summary statistics like r 2 to pick the best model  Don’t compare r 2

Ngày tải lên: 10/01/2018, 16:01

... looking to expand into a new community It has data for 110 cities on the following variables: income, disposable income, birth rate, social security recipients, cardiovascular deaths and percentage ... correlation matrix and the scatterplot matrix 37 of 46 Copyright © 2011 Pearson Education, Inc 4M Example 24.2: RETAIL PROFITS Method Several high correlations are present (shaded in table) and indicate ... PROFITS Method This partial scatterplot matrix identifies communities that are distinct from others Linearity and no lurking variables conditions are met 39 of 46 Copyright © 2011 Pearson Education,

Ngày tải lên: 10/01/2018, 16:01

... 2325.4 Interactions and Inference Interactions and Collinearity Since the interaction in this example is not significant, remove it and re-estimate the MRM Trang 2425.4 Interactions and Inference Parallel ... (e.g., experience). correlated with salary and the two groups (men and women) differ with regard to experience. Trang 725.1 Two-Sample ComparisonSubsets and Confounding Restrict analysis to a ... compare men and women with 5 years of experience) Trang 825.1 Two-Sample ComparisonSubsets and Confounding  The 95% confidence interval for the difference in average salaries between men and women

Ngày tải lên: 10/01/2018, 16:01

... difference between the average yield of Endurance and the others?  Since the variances among groups appear similar, use the two sample t-test and pool the variances Trang 926.1 Comparing Several ... otherwise. D(Hatcher) = 1 if plot grows Hatcher, 0 otherwise. D(NuHills) = 1 if plot grows NuHills, 0 otherwise. D(Ripper) = 1 if plot grows Ripper, 0 otherwise.  J-1 dummy variables are needed to ... Several GroupsWhich Wheat Variety Should a Farmer Plant? Endurance, Hatcher, NuHills, RonL, and Ripper. and yield was measured as bushels per acre. number of observations for each treatment. Trang

Ngày tải lên: 10/01/2018, 16:01

... polynomial for trend and three dummy variables for the four quarters Let Q1 = 1 if quarter 1, 0 otherwise; Q2 = 1 if quarter 2, 0 otherwise; Q3 = 1 if quarter 3, 0 otherwise The fourth quarter ... slow meandering pattern.  Seasonal: cyclical oscillations related to seasons.  Irregular: random variation. Trang 627.1 Decomposing a Time SeriesSmoothing  Smoothing: removing irregular and seasonal ... lags of unemployment and a time trend In other words, use a combination of an autoregression with a polynomial trend. The scatterplot matrix shows linear association and possible collinearity;

Ngày tải lên: 10/01/2018, 16:01

... move up and down or back and forth; undulate 2 to signal with an up and down or back and forth movement of the hand; n 1 a ridge or swell on the surface of a body of water 2 a back -and- ... is a word that sounds the same as another but has a different meaning. Night and knight, for example, are homophones, as are slay and sleigh, great and grate, and bear/bare. There are dozens of ... your exam. HOMOPHONES 103 COMMON HOMOPHONES AND OTHER FREQUENTLY CONFUSED WORDS The following listing shows some of the most common homophones and other frequently confused word pairs along with

Ngày tải lên: 25/10/2013, 17:20