A consumer survey indicates that the average household spends µ = $155 on groceries each week. The distribution of spending amounts to approximately normal with a standard deviation of σ = $25. Based on this distribution:

a. What proportion of the population spends more than $175 per week on groceries?
b. what probability of randomly selecting a family that spends less than $100 per week on groceries?
c. How much money do you need to spend on groceries each week to be in the top 20% of the distribution?

Have you made any attempt on this yet? If so, please post it and someone can check it, because this is pretty much like an entire chapter's worth of explanation.

I did spend quite a bit of time on an example on one thread, and there's some other info on the other thread:

https://www.askmehelpdesk.com/math-sciences/probability-including-finding-using-random-sample-392066.html
https://www.askmehelpdesk.com/math-sciences/probability-390595.html