soap: Dwindling soap

In fastR: Data sets and utilities for Foundations and Applications of Statistics by R Pruim

Description

A bar of soap was weighed after showering to see how much soap was used each shower.

Usage

data(soap)

Format

A data frame with 15 observations on the following 3 variables.

Date

Day

days since start of soap usage and data collection

Weight

weight of bar of soap (in grams)

Details

According to Rex Boggs:

I had a hypothesis that the daily weight of my bar of soap [in grams] in my shower wasn't a linear function, the reason being that the tiny little bar of soap at the end of its life seemed to hang around for just about ever. I wanted to throw it out, but I felt I shouldn't do so until it became unusable. And that seemed to take weeks.

Also I had recently bought some digital kitchen scales and felt I needed to use them to justify the cost. I hypothesized that the daily weight of a bar of soap might be dependent upon surface area, and hence would be a quadratic function ... .

The data ends at day 22. On day 23 the soap broke into two pieces and one piece went down the plughole.

Source

Data collected by Rex Boggs and available from OzDASL (http://www.statsci.org/data/index.html).

Examples

data(soap)
xyplot(Weight~Day,soap)

fastR documentation built on May 2, 2019, 5:53 p.m.