ödev 6

library(wooldridge)

## Warning: package 'wooldridge' was built under R version 4.2.2

library(rmarkdown)

data(murder)

paged_table(murder)

require(dplyr)

## Zorunlu paket yükleniyor: dplyr

## Warning: package 'dplyr' was built under R version 4.2.2

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

summary(lm(mrdrte ~ exec + unem + d90 + d93 , data = murder ))

## 
## Call:
## lm(formula = mrdrte ~ exec + unem + d90 + d93, data = murder)
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -9.130 -3.119 -1.211  1.379 67.810 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)   
## (Intercept)  -1.8644     3.0695  -0.607  0.54452   
## exec          0.1628     0.1939   0.839  0.40268   
## unem          1.3908     0.4509   3.085  0.00243 **
## d90           2.6753     1.8169   1.472  0.14302   
## d93           1.6073     1.7748   0.906  0.36659   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 8.955 on 148 degrees of freedom
## Multiple R-squared:  0.07609,    Adjusted R-squared:  0.05112 
## F-statistic: 3.047 on 4 and 148 DF,  p-value: 0.01897

coklureg<-summary(lm(mrdrte ~ exec + unem + d90 + d93 , data = murder ))

summary(lm(mrdrte ~ exec + unem + d90 + d93 , data = murder ))$sigma

## [1] 8.954822

8.954822^2

## [1] 80.18884

qt(0.95,148)

## [1] 1.655215

data("airfare")

paged_table(airfare)

summary(lm(fare ~ concen + log(dist) + log(dist^2) , data = airfare ))

## 
## Call:
## lm(formula = fare ~ concen + log(dist) + log(dist^2), data = airfare)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -133.75  -46.74  -14.07   41.42  258.57 
## 
## Coefficients: (1 not defined because of singularities)
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) -369.284     12.676  -29.13   <2e-16 ***
## concen        63.133      5.321   11.87   <2e-16 ***
## log(dist)     76.094      1.585   48.00   <2e-16 ***
## log(dist^2)       NA         NA      NA       NA    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 60 on 4593 degrees of freedom
## Multiple R-squared:  0.3583, Adjusted R-squared:  0.358 
## F-statistic:  1282 on 2 and 4593 DF,  p-value: < 2.2e-16

coklureg2<-summary(lm(fare ~ concen + log(dist) + log(dist^2) , data = airfare ))$sigma

confint(summary(lm(fare ~ concen + log(dist) + log(dist^2) , data = airfare )))

##      2.5 % 97.5 %