stat340: Data and functions for BIAS at NMBU

#' boilers: Erecting Boiler Drums
#'
#' This data contains man-hours required to erect boiler drums of two types:
#' steam and mud drums. A manufacturer of boiler drums wants to use regression
#' to predict the number of hours needed to erect the drums in future projects.
#' To accomplish this, information of 35 boilers were collected; the boiler
#' design pressure in pounds per square inch (PSI), boiler capacity and if the
#' boiler was industry field erected or utility field erected.
#'
#' @format A data frame with 36 observations (rows) and 5 variables (columns).
#'
#' \tabular{llllr}{
#'   \tab \bold{Column name} \tab \bold{Data type} \tab \bold{Description} \tab \bold{Values}\cr
#'   \code{[,1]} \tab \code{Hours} \tab integer \tab Man-hours \tab (1200 - 14791)\cr
#'   \code{[,2]} \tab \code{Capacity} \tab integer \tab Boiler capacity in lb/hour \tab (30000 - 1089490)\cr
#'   \code{[,3]} \tab \code{Pressure} \tab integer \tab Boiler design pressure in PSI \tab (250 - 2170)\cr
#'   \code{[,4]} \tab \code{Boiler} \tab integer \tab 1 if industry erect, otherwise 0 \tab (0 - 1)\cr
#'   \code{[,5]} \tab \code{Drum} \tab integer \tab Steam drum = 1, mud drum = 0 \tab (0 - 1)
#' }
#'
#' @details
#'
#' A boiler is used to provide hot water or steam for heating. The steam drum is
#' located in the upper drum of a boiler and used to store the steam generated
#' in water-tube boilers. A mud drum, which is the lower drum, can be added to
#' the system to collect and remove sediments and mud in the water.
#'
#'
#' This data is from Exercise 4.74 in A second course in statistics: Regression
#' Analysis, 7th edition.
#'
#' @examples
#'
#' # First eight rows
#' head(boilers, n = 8)
#'
#' # Man-hours for industry erected mud boiler drums
#' idx <- which(boilers$Boiler == 1 & boilers$Drum == 0)
#' boxplot(boilers$Hours[idx] ~ boilers$Pressure[idx])
#'
#' @source
#'
#' Mendenhall, W., Sincich, T. (2012) \emph{A second course in statistics:
#' Regression Analysis, 7th edition.} Pearson Education.
#'
#' @docType data
#' @keywords datasets
#' @name boilers
#' @usage boilers
#'
"boilers"