WGU C955 - Module 5 Descriptive Statistics for Two Variables Exam Questions With Correct Answers

The relationship between the two variables on a scatterplot can be measured by what statistic? {{ Scatterplot of sales on the x-axis and profit index on the y-axis. }} a Correlation coefficient ( r ) b Regression c ANOVA d Chi-square - Answer Correlation coefficient ( r ) A study was completed to investigate if commutes of longer than 30 minutes increased the risk of burnout. The results of the study are in the table below. ,Lenth of Commute ,<30 Minutes ,>30 Minutes ,Total Risk of Burnout ,Negative for Burnout ,185 ,72 ,257 ,Positive for Burnout ,98 ,247 ,345 ,Total ,283 ,319 ,602 What percentage of commuters with commutes greater than 30 minutes expressed being burned out? a 66.39% b 77.43% c 81.62% d 70.74% - Answer 77.43% Describe the relationship of the two variables on the scatterplot. {{ Scatterplot displaying data points with advertising dollars on the x-axis and units sold on the y-axis. The data points are tightly clustered in a pattern that slopes upward from right to left in a non-linear fashion. }} a Weak negative b Strong negative c Weak/No relationship d Non-linear/Curved relationship - Answer Non-linear/Curved relationship What percentage of connections using Service Provider A were suspicious? Web Hosting Service Service Provider A Service Provider B Total Web Server Safe Connections 87 14 101 Suspicious Connections 37 89 126 Total a 13.6% b 29.8% c 70.2% d 86.4% - Answer 29.8% Out of the total number of connections, what percentage of safe connections were reported by Service Provider A? Web Hosting Service Service Provider A Service Provider B Total Web Server Safe Connections 87 14 101 Suspicious Connections 37 89 126 Total a 6.2% b 16.3% c 38.3% d 39.2% - Answer 38.3% In the side-by-side box plot below, gender represents what type of variable? {{ Side by side box plots comparing the hourly wages of both males and females. Gender is on the y-axis }} a Quantitative variable b Response variable c Controlled variable d Categorical variable - Answer Categorical variable What percentage of the students who took the eight-week online course were unsuccessful in passing the certification exam? Successful Unsuccessful Total Eight Week Online Certification Course Self-directed Certification Study Program 42 14 56 Total a 7.3% b 18.1% c 20% d 25.6% - Answer 18% In the side-by-side box plot below, hourly wage represents what type of variable? {{ Side by side box plots comparing hourly wages of both males and females. Hourly wage is on the x-axis. }} a Response variable b Categorical variable c Explanatory variable d Qualitative variable - Answer Response variable What is the joint frequency of safe connections for Service Provider A? Web Hosting Service Service Provider A Service Provider B Total Web Server Safe Connections 87 14 101 Suspicious Connections 37 89 126 Total a 14 b 37 c 87 d 89 - Answer 87 What type of correlation is shown in the scatterplot? {{ Scatterplot displaying data points distributed in a line descending from upper left to lower right. }} a Perfectly linear positive b Perfectly linear negative c Strong but not perfectly linear positive d Strong but not perfectly linear negative - Answer Perfectly linear negative A study was completed to investigate if commutes of longer than 30 minutes increased the risk of burnout. The results of the study are in the table below. Lenth of Commute <30 Minutes >30 Minutes Total Risk of Burnout Negative for Burnout Positive for Burnout Total What percentage of commuters that did not report feeling burned out have a commute of fewer than 30 minutes? a 78.61% b 71.98% c 68.24% d 80.78% - Answer 71.98% On this scatterplot, what do the five points in the upper left corner near (3,12) represent? {{ Scatterplot displaying data points in a line from lower left to upper right, with a grouping of data points in the upper left quadrant. }} a Outlier b Cluster c Trend d Correlation - Answer Cluster What does the point of (4,12) represent on this scatterplot? {{ Scatterplot displaying data points distributed in a line from lower left to upper right, with one data point in the upper left quadrant. }} a Outlier b Cluster c Trend d Correlation - Answer Outlier In the scatterplot, sales represent what type of variable? {{ Scatterplot of sales on the x-axis and profit index on the y-axis. }} a Qualitative variable b Explanatory variable c Response variable d Controlled variable - Answer Response variable What is the marginal frequency of suspicious connections? Web Hosting Service Service Provider A Service Provider B Total Web Server Safe Connections 87 14 101 Suspicious Connections 37 89 126 Total a 101 b 126 c 124 d 103 - Answer 126 If both variables are quantitative, what graphical display can show whether there is a relationship between the variables, the strength of the relationship, and whether it is positive or negative? a Histogram b Scatterplot c Two-way frequency table d Gantt chart - Answer Scatterplot What type of correlation is shown in the scatterplot? {{ Scatterplot illustrating data points widely distrubted with no apparent trend. }} a Positive correlation b Negative correlation c Non-linear correlation d No correlation - Answer No correlation What percentage of connections using Service Provider B were suspicious? Web Hosting Service Service Provider A Service Provider B Total Web Server Safe Connections 87 14 101 Suspicious Connections 37 89 126 Total