Merge pull request #1 from mine-cetinkaya-rundel/master

update reference for smoking dataset + new data: gpa_study_hours

openintro/man/gpa_study_hours.Rd

@@ -0,0 +1,31 @@
+\name{gpa_study_hours}
+\alias{gpa_study_hours}
+\docType{data}
+\title{gpa_study_hours}
+\description{
+A data frame with 193 rows and 2 columns. The columns represent the variables \code{gpa} and \code{study_hours} for a sample of 193 undergraduate students who took an introductory statistics course in 2012 at a private US university.
+}
+\usage{data(gpa_study_hours)}
+\format{
+  A data frame with 193 observations on the following 2 variables.
+  \describe{
+    \item{\code{gpa}}{ Grade point average (GPA) of student. }
+    \item{\code{study_hours}}{ Number of hours students study per week. }
+  }
+}
+\details{
+GPA ranges from 0 to 4 points, however one student reported a GPA > 4. This is a data error but this observation has been left in the dataset as it is used to illustrate issues with real survey data. Both variables are self reported, hence may not be accurate.
+}
+\source{
+Collected at a private US university as part of an anonymous survey in an introductory statistics course.
+}
+\references{
+}
+\examples{
+data(gpa_study_hours)
+
+#===> gap vs. study hours <===#
+plot(gpa_study_hours$gpa ~ gpa_study_hours$study_hours, xlab="Study hours/week", ylab = "GPA", pch=20, col = COL[1,2])
+
+}
+\keyword{datasets}

openintro/man/smoking.Rd

@@ -26,7 +26,7 @@ Survey data on smoking habits from the UK. The data set can be used for analyzin
   }
 }
 \source{
-\url{http://www.stats4schools.gov.uk/large_datasets/smoking/default.asp}
+National STEM Centre, Large Datasets from stats4schools, \url{http://www.nationalstemcentre.org.uk/elibrary/resource/3624/large-datasets-from-stats4schools}.
 }
 \examples{
 data(smoking)