The `Amsterdamsche Bos' Forestry wishes to estimate the total wood volume of the trees on its domain.

To this end, the Forestry has cut a sample of 59 trees of their most prevalent type `Beech' and `Oak'.

The volume of these trees alongside their height and trunk diameter have been measured. The latter two characteristics can be measured in the eld without sacrificing the tree. The Forestry hypothesizes that these are predictive of the tree's volume. The file treeVolume.txt (https://ideone.com/lvmqqh) (you can save the file as 'treeVolume') from the cut trees is to uncover this relationship, taking into account the tree type.

I want to figure out this question coding in R:

What are the estimated volumes for the two tree types with average diameter and height?

I have this code below, but I can't find the answer in two tree types with the average diameter and height.

The response should give us one average number in [fit], [lower], [upper] for each type of tree as well as diameter and height, but my code shows every 59 rows.

diameter<-treeVolume[,1] diameter height <-treeVolume[,2] height volume<-treeVolume[,3] volume type<-treeVolume[,4] type predict(lm(volume ~ type + diameter + height), treeVolume, interval = 'prediction')

*'predict' function is a must.

Thank you!