Introduction - If you have any usage issues, please Google them yourself
## Summarizes data.
## Gives count, mean, standard deviation, standard error of the mean, and confidence interval (default 95 ).
## data: a data frame.
## measurevar: the name of a column that contains the variable to be summariezed
## groupvars: a vector containing names of columns that contain grouping variables
## na.rm: a boolean that indicates whether to ignore NA s
## conf.interval: the percent range of the confidence interval (default is 95 )