do you think the Inspiron 7567 with a 74wh battery is sufficient?
The Dell 7567 will last about 6 hours for normal usage and 1 and a half hours if you are playing games (pls refer to the video reviews). But do bear in mind the terrible TN screen, the weight, the cost, etc...which I talked about.
If you are really concerned about the battery life, you need to ask yourself these few questions. Do you need a discrete GPU (e.g. GTX 1050Ti) in your laptop for your course? Or you have very limited space at home such that you can only accommodate a laptop? Do you intend to game when outside? You will also have to factor in the weight for other stuff that you will be carrying such as your books, files, notes, water bottle, etc...
If you only need to use Microsoft Office/less demanding programs or you have a gaming PC at home or you don't plan on gaming when outside, then it's not necessary to buy a bulky and power hungry gaming laptop for your studies. Instead you should consider getting a lightweight and more power efficient laptop e.g. ultrabook.
Before you buy your laptop, please go to the showroom or retail store to have an actual feel of the laptop (i.e. check the screen quality, keyboard, weight, build quality, etc...). Also try bargaining with the salespeople or get freebies and do ask them if you have any questions about the laptop.
Lastly, you can take our comments and reviews as a guide, but no point buying something based on comments/reviews and then finding out it's not suitable for your usage. Hopefully, you can find a laptop that suits your needs.