Numeric. Either a vector of length 2 with attribute conf.level or a two-column matrix
and confidence region bounds as column names (e.g. "2.5 %" and "97.5 %") and coefficient names as row names.
conf_level
Numeric. Vector of length 2 giving the lower and upper bounds of the confidence region in case
they cannot be determined from column names or attributes of x.
use_math
Logical. Indicates whether to insert $ into the output so that Inf or scientific
interval_type
Character. Abbreviation indicating the type of interval
estimate, e.g. CI.