Question

Age   Browsing Time (min/wk)
34   372
48   198
24   469
33   387
43   262
58   85
20   469
49   192
64   86
55   119
46   233
36   345
35   357
29   415
37   327

​d) Check the residuals to see if the conditions for inference are met.

The equal spread condition IS/IS NOT satisfied because the scatterplot of the residuals against the predicted values shows NO PATTERN/A THICKENING OF THE SPREAD/A THINNING OF THE SPREAD/A CURVATURE.

.The nearly normal condition IS/IS NOT satisfied because the Normal probability plot SHOWS/DOES NOT SHOW an approximately straight line. ​ (This is also the case because a histogram of the residuals IS APPROXIMATELY/IS NOT unimodal and​symmetric.)

The outlier condition IS/IS NOT satisfied because the Normal probability plot SHOWS SOME/DOES NOT SHOW ANY extreme outliers.

Answer 1

Sol:

Rcode:

df=read.table(header = TRUE, text ="
Age BrowsingTime
34 372
48 198
24 469
33 387
43 262
58 85
20 469
49 192
64 86
55 119
46 233
36 345
35 357
29 415
37 327

"
)
df

linmod <- lm(BrowsingTime~Age,data=df)
plot(linmod,which=1)

plot(linmod,which=2)

plot(linmod,which=3)

plot(linmod,which=4)

The equal spread condition IS satisfied because the scatterplot of the residuals against the predicted values shows NO PATTERN

.The nearly normal condition IS satisfied because the Normal probability plot SHOWS an approximately straight line. ​ (This is also the case because a histogram of the residuals IS APPROXIMATELY unimodal and​symmetric.

The outlier condition IS NOT satisfied because the Normal probability plot SHOWS SOME extreme outliers.