2019年度 データ解析基礎論a T検定

x.temp = 0:11
m = dbinom(x.temp, 11, prob=0.5)
names(m) <- paste(0:11)
barplot(m, col = c(rep("red",3),rep("red",6),rep("red",3)))

ssize = c(24,25,26,23.5,25,27,24,22,27.5,28)ssize.mean = mean(ssize)
ssize.var = var(ssize)
N = 10
t.value=(ssize.mean-24)/(sqrt(ssize.var/N))

x.temp = seq(-4,4,0.01)
y.temp = dt(x.temp,df = 9)
plot(x.temp,y.temp, type='l',lwd=3,ylab = "Density", xlab = 't-value')
abline(v = t.value, col='red',lwd=3,lty=2)
abline(v = -t.value, col='red',lwd=3,lty=2)

A=c(12,19,10,10,14,18,15,11,16)
B=c(15,20,16,14,17,16,12,12,19)
d=A-B
tValue<-mean(d)/sqrt(var(d)/length(d))
(1-pt(abs(tValue), df=8))*2
x.temp = seq(-4,4,0.01)
y.temp = dt(x.temp,df = 8)
plot(x.temp,y.temp, type='l',lwd=3,ylab = "Density", xlab = 't-value')
abline(v = t.value, col='red',lwd=3,lty=2)
abline(v = -t.value, col='red',lwd=3,lty=2)

X1=c(78,70,66,76,78,76,88,76)
X2=c(76,72,60,72,70,72,84,70)
t.value=(mean(X1)-mean(X2))/sqrt((var(X1)+var(X2))/8)
2*(1-pt(abs(t.value),14))