xmp10.05 {Devore6} | R Documentation

## data from Example 10.5

### Description

The `xmp10.05` data frame has 20 rows and 2 columns of data from an experiment on the effect of alcohol on REM sleep time

### Format

This data frame contains the following columns:

REMtime
  a numeric vector giving the rapid eye movement (REM) sleep time for each rat during a 24-hour period
ethanol
  a numeric vector giving the concentration of ethanol (alcohol) per body weight administered to the rat (g/kg)

### Details

### Source

Devore, J. L. (2003) Probability and Statistics for Engineering and the Sciences (6th ed), Duxbury

(1978), ``Relationship of ethanol blood level to REM and non-REM sleep time and distribution in the rat'', Life Sciences, 839-846.

### Examples

    data(xmp10.05)
    plot(REMtime ~ ethanol, data = xmp10.05,
         xlab = "Ethanol concentration administered (g/kg)",
         ylab = "Amount of REM sleep during a 24 hour period")
    fm1 <- lm(REMtime ~ factor(ethanol), data = xmp10.05)
    anova(fm1)      # compare with Table 10.4, p. 417
    summary(fm1)    # differences with baseline (0 g/kg)
    ##  more appropriate to use an ordered factor
    fm2 <- lm(REMtime ~ ordered(ethanol), data = xmp10.05)
    anova(fm2)      # same as above
    summary(fm2)    # polynomial contrasts
    ##  best model uses square root of ethanol concentration
    plot(REMtime ~ sqrt(ethanol), data = xmp10.05,
         xlab = expression(sqrt(
            plain("Ethanol concentration administered (g/kg)"))),
         ylab = "Amount of REM sleep during a 24 hour period")
    fm3 <- lm(REMtime ~ sqrt(ethanol), data = xmp10.05)
    summary(fm3)
    abline(fm3)
    anova(fm3, fm1)   # lack of fit test
    opar <- par(mfrow = c(2,2))
    plot(fm3, main = "Continuous fit to data in Example 10.5")
    par(opar)

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