.summary_mean_ci: Wrapper to calculate summary mean with 95% confidence interval
Description
This internal function calculates summary mean and 95% confidence interval of the utility variable, which can also be grouped.
The function is used in Figures 4.2-4.4.
Usage
.summary_mean_ci(df, group_by)
Value
A data frame with the mean, lower bound, and upper bound of the 95