Single Samples

The body temperatures of five patients diagnosed to have a virus are

99.2

99.6

99.9

100.4

98.9

To obtain a 95% confidence interval for the population mean body temparature of patients with this virus, use

temp<-c(99.2,99.6,99.9,100.4,98.9) t.test(temp)

The result should look like this (ignore the p-value information):

         One Sample t-test 

data:  temp 
t = 379.1707, df = 4, p-value = 2.903e-10 
alternative hypothesis: true mean is not equal to 0 
95 percent confidence interval:
  98.87069 100.32931 
sample estimates:
mean of x 
     99.6

For a 90% interval, provide the confidence level with the conf.level argument.

temp<-c(99.2,99.6,99.9,100.4,98.9) t.test(temp, conf.level = 0.9)

To test the hypothesis that the mean body temperature for patients with the virus is 98.6 against the alternative that it is higher, use

temp<-c(99.2,99.6,99.9,100.4,98.9) t.test(temp,mu=98.6,alternative="greater")

The result should look like this (ignore the confidence interval information this time):

         One Sample t-test 

data:  temp 
t = 3.8069, df = 4, p-value = 0.009495 
alternative hypothesis: true mean is greater than 98.6 
95 percent confidence interval:
 99.04    NA 
sample estimates:
mean of x 
     99.6

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Work Area

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