1. The CO2 dataset has 84 rows and 5 columns of data from an experiment on the cold tolerance of the grass species Echinochloa crus-galli. plant: an ordered factor with levels Qn1 < Qn2 < Qn3 < … < Mc1 giving a unique identifier for each plant. type: a factor with levels Quebec Mississippi giving the origin of the plant treatment: a factor with levels nonchilled chilled conc: a numeric vector of ambient carbon dioxide concentrations (mL/L). uptake: a numeric vector of carbon dioxide uptake rates (umol/m^2 sec).

    Test whether the population mean uptake is less than 30 or not with 5% level of significance

data(CO2)
t.test(CO2$uptake,mu=30,alternative = "l")
## 
##  One Sample t-test
## 
## data:  CO2$uptake
## t = -2.3619, df = 83, p-value = 0.01026
## alternative hypothesis: true mean is less than 30
## 95 percent confidence interval:
##      -Inf 29.17585
## sample estimates:
## mean of x 
##   27.2131

Reject H0 at 5% level of significance.

Conclusion: Population mean uptake may be less than 30.

  1. The Indometh data frame has 66 rows and 3 columns of data on the pharmacokinetics of indometacin (or, older spelling, ‘indomethacin’). Subject an ordered factor with containing the subject codes. The ordering is according to increasing maximum response. time a numeric vector of times at which blood samples were drawn (hr). conc a numeric vector of plasma concentrations of indometacin (mcg/ml). Test whether the population mean for Plasma Concentration is greater than 0.30 at 5% level of significance
data("Indometh")
t.test(Indometh$conc,mu=0.3,alternative = "g")
## 
##  One Sample t-test
## 
## data:  Indometh$conc
## t = 3.7477, df = 65, p-value = 0.0001908
## alternative hypothesis: true mean is greater than 0.3
## 95 percent confidence interval:
##  0.4618886       Inf
## sample estimates:
## mean of x 
## 0.5918182

Reject H0 at 5% level of significance

Result: Population mean for Plasma Concentration may be greater than 0.30.