assignment 4

power.t.test(n=NULL, delta = .015, sd= .03, sig.level= .05, power= .75, type = c("paired"), alternative= c("one.sided"))

## 
##      Paired t test power calculation 
## 
##               n = 22.92961
##           delta = 0.015
##              sd = 0.03
##       sig.level = 0.05
##           power = 0.75
##     alternative = one.sided
## 
## NOTE: n is number of *pairs*, sd is std.dev. of *differences* within pairs

library(pwr)
pwr.t.test(n=NULL,d=.5, sig.level = .1,power = .85,type = c("two.sample"),alternative = c("greater"))

## 
##      Two-sample t test power calculation 
## 
##               n = 43.40568
##               d = 0.5
##       sig.level = 0.1
##           power = 0.85
##     alternative = greater
## 
## NOTE: n is number in *each* group