Straighterline Introduction to Statistics Exam Questions and Answers Four steps in the process of statistics -Answer -1. Producing Data 2. Exploratory Data Analysis 3. Probability 4. Inference Categorical variable -Answer -places individuals into one of several groups Two types: nominal and ordinal Quantitative Variable -Answer -represents a measurement or a count Two types: Interval and ratio Nominal Variable -Answer -categorical variables where t here is no natural order among the categories Ordinal variable -Answer -categorical variables where there is natural order among the categories Interval Variable -Answer -a measurement or count for which it makes sense to talk about the difference between va lues, but it does not make sense to talk about the ratio between values; 0 does not represent the absence of quanitity Ratio Variable -Answer -quantitative variables for which it makes sense to talk about the difference between values AND the ratio between values; 0 represents the absence of quantity What type of variable?: eye color -Answer -nominal What type of variable?: socioeconomic status with categories low, med, high -Answer -Ordinal What type of variable?: Temperature -Answer -Interval What type of var iable?: Income -Answer -Ratio Visual display and numerical summary for a single categorical variable -Answer -pie chart or bar chart and category percentages Visual display and numerical summary for a single quantitative variable -Answer -
histogram or stemplo t and descriptive statistics Visual display and numerical summary for C ->C -Answer -Two way table and conditional percentages Visual display and numerical summary for C ->Q -Answer -Side by side box plots and descriptive statistics Visual display and numerical summary for Q ->Q -Answer -Scatterplot and correlation coefficient (r) Standard Deviation Rule -Answer -Approximately 68% of observations fall within 1 sd of the mean, 95% within 2 sd, 99.7% (or virtually all) within 3 sds Interquartile Range (IQR) -Answer -Middle 50% of the data
histogram or stemplo t and descriptive statistics Visual display and numerical summary for C ->C -Answer -Two way table and conditional percentages Visual display and numerical summary for C ->Q -Answer -Side by side box plots and descriptive statistics Visual display and numerical summary for Q ->Q -Answer -Scatterplot and correlation coefficient (r) Standard Deviation Rule -Answer -Approximately 68% of observations fall within 1 sd of the mean, 95% within 2 sd, 99.7% (or virtually all) within 3 sds Interquartile Range (IQR) -Answer -Middle 50% of the data
