Section 18 t.test

18.1 Subset and summarise data

• Subset the BP data as a new data.frame pBP with only two Groups A & B

• Obtain the mean and sd of SBP for Groups A & B

• Create appropriate plots to compare the data on SBP between Groups A & B

18.2 t.test

• Perform the t.test to compare if the mean difference for SBP between Group A and B is significantly different.

• Examine the R object of the t.test outputs.

• Write your own function to conduct the t.test.