I have 2 other questions on hypothesis testing.
If I have a hypothesis like this:
Spanish companies have more contract offers from Portuguese companies, than German companies have from Portuguese companies.
Now I have 2 questions:
1- To test this imagine, I choose 100 Spanish companies randomly and 100 German companies, and ask them for number of contract offers they received from Portuguese companies, but I don't want to limit them to just one year (for doing a more thorough test), so I ask them to give me the number of contract offers they received for a range of years (for example, instead of asking them for data of just year 2014, I ask them for data from 2000 to 2014). But some companies haven't been yet existed in 2000, so, they don't have data for those years. Can I collect data, and make an average per year and use that to do my test?
For example, company A has been started from year 2004 and till end of 2014 had an average of 10 contract offers per year, and company B has been started from 1910 and between 2000 and 2014 had an average of 12 contract offers per year. Can I treat both of these data equally or should I eliminate the companies that have been established after year 2000. Or is there any other way to solve this problem?
2- Another question is, can I choose 100 Spanish companies and 200 German companies, and compare the difference between the means? Or I should choose equal number of companies from both countries (for example 100 Spanish companies and 100 German companies)?
Thank you in advance