WGU C784-Statistics Mod 4 Exam Questions and Answers

Define Mode - Answer- The value that occurs most often in a data set The Mean of a data set represents the? - Answer- Average Median of a data set - Answer- The middle value of the data set What are the two types of variables - Answer- 1) Quantitative Variable 2) Categorical Variable Quantitative variable - Answer- Quantitative variable - a variable that takes a numerical value that can be counted or measured. Examples: height, weight, age, cholesterol level, exam scores Categorical variable - Answer- Categorical variable - a variable that is not measured; it is a "category" or a label; it places the individual in a certain group. Examples: gender, months of the year, zip codes List Two Graphical Displays for Categorical Data - Answer- 1) Pie Charts 2) Bar Charts ___________________ - best when we want to display different parts of a whole - Answer- Pie Charts. _______________________ - best to display counts or frequencies for the categories - Answer- Bar Charts. List the 4 different Graphical Displays for Quantitative Data - Answer- Dot Plot - Best to display the distribution of data, particularly clusters, gaps, and outliers. Most useful for smaller data sets. Stem Plot (or Stem and Leaf Plot) - Best to display the distribution or shape of data according to place values. Keeps information about individual data points. Box Plot - Best to display the center, spread, and outliers of a given data set. Histogram - Best to display the distribution (shape and spread) of quantitative data. Works well with large data sets. A stem plot is constructed by separating each data value into a stem and a leaf. The leaf is the __________ most digit, and the stem consists of all of the digits to the __________ of the leaf. - Answer- A stem plot is constructed by separating each data value into a stem and a leaf. The leaf is the right most digit, and the stem consists of all of the digits to the left of the leaf. Note: Represent each number that is in the ones place from the list of numbers. By doing this the stems will consist of ones, twos, threes, and fours. Next list the leafs by taking the digit to the right and writing it within the coloumn/stem that matches the ones place holder of the number. Example 31 the ones place/ stem is "3" the Leaf which is to the right of the number is "1". After listing all stems and leafs. Re-arrange them in increasing order. If the list of numbers is long or big you can split the stem and leaf into two sets. Ex. the first stem set of 1 will list any leafs 1-5 while the second stem leaf set can list any leafs 6-9. See thirs graph for illustration What 4 analysis are needed to describe a distribution - Answer- 1. The shape of the graphical display 2. The center and spread of the data 3. The maximum and minimum values 4. Any values that could be outliers