Please help with these questions

[AnnittaM]

1. The list files command tells you there are 2 folders, Documents and Downloads, in the directory in which you are located. Using your preferred shell scripting language, how would you obtain a list of all the csv files located within the Documents folder?

2. Given a dataframe with daily revenue data by state from 2010 to present day, write a pandas transformation using method chaining to calculate a Month over Month percentage change for each state from 2019 through 2020. df.columns = ['state', 'year', 'month', 'day', 'revenue']

3. A BigQuery/SQL table contains columns [date, spend, adgroup, installs]. Write a query that returns the mean cost per install for each adgroup as well as the percentage of total spend that each adgroup had. Organize the results by descending mean cost per install.