Exam 1 Review

Five questions

1)     First question is from the first topic about numerical summaries/bar graphs/box plots/ distributions

Small data set will be given – calculate mean, median, mode, range, Q1, Q2, Q3, IQR, Outliers

IQR = Q3 – Q1

Lower bound = Q1 – 1.5 (IQR) > Outliers

Upper bound = Q2 + 1.5 (IQR) < Outliers

Draw boxplot and analyze distribution – NEED calculator

2). Variable types / level of measurements

Qualitative and quantitative (Discrete and continuous)

Level of measurements:

1). Nominal (Just name/categories) e.g. eye color Qualitative

2). Ordinal (Categories with order) e.g. level of education Qualitative

3). Interval (No true meaning for 0) e.g. temperature/credit score Quantitative

4). Ratio (True meaning for 0) e.g. height Quantitative

3). Study types

Observational / Experimental

Experimental Terminology:

Experimental Units: the individuals or item (subjects/objects) on which the experiment is performed

Variables:

Independent variables: Predictors/Factors/Explanatory variables (X), we can change the value of this variable

Dependent variables: Response variable (Y), to observe the effect that the independent variable has on the individual (or simply dependent variables depend on the independent variables).

Levels: The different possible categories/groups of factor variables

Treatments: A specific experimental condition applied to the experimental units on experiments.

·       One-factor experiment: The treatments are the levels of the single factor. E.g. gender, the levels are the different categories of gender (they are equal).

Multi-factor experiment: Each treatment is a combination of levels of factors. E.g. combination of sex (Male) and smoking. Individual from male group and smoking group is an example of one treatment.

4). Sampling techniques

Probability and non-probability sampling

Probability: Simple Random Sampling, Systematic, Stratified, Cluster

Non-Probability: Convenience, Purposive, Snowball, Voluntary Response, Quota

Give us several descriptions and we must give which technique is being used.

5). Probability

- Sample space is the collection of all possible outcomes

- Event: Any collection of possible outcomes

P(A) = N(A)/N(S) – number of elements in the sample space

Probability is always between 1 and 0

Part 1: Must find the probability of different events in a sample space

Part 2: Probability trees / probability for multiple events. Two options with replacement and without replacement