library(resampledata)

## 
## Attaching package: 'resampledata'

## The following object is masked from 'package:datasets':
## 
##     Titanic

data(Beerwings)
attach(Beerwings)
beerwingmodel <- lm(Hotwings ~ Beer)

ConfidenceIntervals

confint(beerwingmodel,level=.9)

##                   5 %      95 %
## (Intercept) 1.3217981 5.9440620
## Beer        0.2361993 0.3974193

Correlation

cor(Hotwings,Beer)

## [1] 0.7841224

cor(Beer,Hotwings)

## [1] 0.7841224

prediction & confidence intervals

newdata <- data.frame(Beer=30)
seconddata <- data.frame(Beer=12)

(predint <- predict(beerwingmodel,newdata,interval="predict"))

##        fit      lwr      upr
## 1 13.13721 6.834041 19.44038

(confinn <- predict(beerwingmodel,newdata,interval="confidence"))

##        fit     lwr      upr
## 1 13.13721 11.9484 14.32602

predint %*% c(0,-1,1)

##       [,1]
## 1 12.60634

confinn %*% c(0,-1,1)

##       [,1]
## 1 2.377623

predint[1] == confinn[1]

## [1] TRUE