* minor typos in last exercise in common problems
* unusually easiest -> unusually easy
* move mapping(aes()) into geom to match other ggplot calls
* wording suggestion in exercise + typo fix
* feel be free -> feel free
* and new dataset -> and a new dataset, missing a
* dplyr overwrite's'
Also changed spellings to British English for consistency.
FYI. Table number of light speed measurements currently reads (#tab:variation). The code appears to be correct.
Mine Cetinkaya-Rundel
hadley
Bill Behrman
Terence Teo
OaCantona