MultiLinear Regression

Computer Data set

sales <- read.csv("D://Users//jayapate//Downloads//Computer_Data.csv")
attach(sales)
plot(sales)

sales1 <- sales[-c(1,7,8,9)]
View(sales1)
plot(sales1)

#To check the correlation of Sales
cor(sales1)
##              price      speed         hd        ram      screen
## price   1.00000000  0.3009765  0.4302578  0.6227482  0.29604147
## speed   0.30097646  1.0000000  0.3723041  0.2347605  0.18907412
## hd      0.43025779  0.3723041  1.0000000  0.7777263  0.23280153
## ram     0.62274824  0.2347605  0.7777263  1.0000000  0.20895374
## screen  0.29604147  0.1890741  0.2328015  0.2089537  1.00000000
## ads     0.05454047 -0.2152321 -0.3232220 -0.1816697 -0.09391943
## trend  -0.19998694  0.4054383  0.5777901  0.2768438  0.18861444
##                ads      trend
## price   0.05454047 -0.1999869
## speed  -0.21523206  0.4054383
## hd     -0.32322200  0.5777901
## ram    -0.18166971  0.2768438
## screen -0.09391943  0.1886144
## ads     1.00000000 -0.3185525
## trend  -0.31855251  1.0000000
colnames(sales1)
## [1] "price"  "speed"  "hd"     "ram"    "screen" "ads"    "trend"
#Multi Linear Model
model1 <- lm(price~speed+hd+ram+screen+ads+trend)
summary(model1)
## 
## Call:
## lm(formula = price ~ speed + hd + ram + screen + ads + trend)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -929.36 -191.78  -32.22  134.49 1949.91 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept) -246.67547   66.37087  -3.717 0.000204 ***
## speed          8.89391    0.20883  42.590  < 2e-16 ***
## hd             0.70882    0.03091  22.932  < 2e-16 ***
## ram           47.38704    1.18767  39.899  < 2e-16 ***
## screen       126.70240    4.52146  28.022  < 2e-16 ***
## ads            0.96969    0.05671  17.099  < 2e-16 ***
## trend        -47.08197    0.67588 -69.660  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 311.7 on 6252 degrees of freedom
## Multiple R-squared:  0.7123, Adjusted R-squared:  0.712 
## F-statistic:  2580 on 6 and 6252 DF,  p-value: < 2.2e-16