Hint: The data file is posted in Moodle. See Module 5. It’s named as “gapminder.csv”.
## country continent year lifeExp pop gdpPercap
## 1 Afghanistan Asia 1952 28.801 8425333 779.4453
## 2 Afghanistan Asia 1957 30.332 9240934 820.8530
## 3 Afghanistan Asia 1962 31.997 10267083 853.1007
## 4 Afghanistan Asia 1967 34.020 11537966 836.1971
## 5 Afghanistan Asia 1972 36.088 13079460 739.9811
## 6 Afghanistan Asia 1977 38.438 14880372 786.1134
## country continent year lifeExp
## Length:1704 Length:1704 Min. :1952 Min. :23.60
## Class :character Class :character 1st Qu.:1966 1st Qu.:48.20
## Mode :character Mode :character Median :1980 Median :60.71
## Mean :1980 Mean :59.47
## 3rd Qu.:1993 3rd Qu.:70.85
## Max. :2007 Max. :82.60
## pop gdpPercap
## Min. :6.001e+04 Min. : 241.2
## 1st Qu.:2.794e+06 1st Qu.: 1202.1
## Median :7.024e+06 Median : 3531.8
## Mean :2.960e+07 Mean : 7215.3
## 3rd Qu.:1.959e+07 3rd Qu.: 9325.5
## Max. :1.319e+09 Max. :113523.1
Hint: For the code, refer to one of our textbooks, Data Visualization with R: Chapter 4.2. Map lifeExp to the y-axis and gdpPercap to the x-axis.
Hint: Interpret both the direction and the strength of the correlation
## [1] 1
The Pearson correlation coefficient is 1 meaning that the two variables are perfectly positively linear.
Yes because the scatterplot shows that a low gdp has a wide range of life expectancy. Once the gdp rises, the life expectancy is mostly higher numbers.
Hint: For the code, refer to one of our textbooks, Data Visualization with R: Chapter 8.1.
## year lifeExp pop gdpPercap
## year 1.00 0.44 0.08 0.23
## lifeExp 0.44 1.00 0.06 0.58
## pop 0.08 0.06 1.00 -0.03
## gdpPercap 0.23 0.58 -0.03 1.00
There are no other variables with a strong positive association with life expectancy besides gdp.
Hint: A correct answer must include all of the following: 1) direction and strength of the correlation coefficient, and 2) linear versus non-linear relationship.
The direction of the correlation coefficient is upward sloping which means that it is positively related. ## Q8 Hide the messages, but display the code and its results on the webpage. Hint: Use message, echo and results in the chunk options. Refer to the RMarkdown Reference Guide.